chore: Align LICENSE and NOTICE with ASF policy

LICENSE

@@ -202,117 +202,28 @@
 
 --------------------------------------------------------------------------------
 
-3rdparty dependency nlohmann-json is statically linked in certain binary
-distributions. nlohmann-json has the following license:
+This product includes code from smhasher.
 
-MIT License
+* src/iceberg/murmur3_internal.h and src/iceberg/murmur3_internal.cc are adapted from MurmurHash3.
 
-Copyright (c) 2013-2022 Niels Lohmann
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-
---------------------------------------------------------------------------------
-
-The file src/iceberg/murmur3_internal.h contains code adapted from
-
-https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.h
-
-The file src/iceberg/murmur3_internal.cc contains code adapted from
-
-https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp
-
-MurmurHash3 was written by Austin Appleby, and is placed in the public
-domain. The author disclaims copyright to this source code.
+Copyright: Austin Appleby (placed in the public domain).
+Home page: https://github.com/aappleby/smhasher
+License: Public Domain
 
 --------------------------------------------------------------------------------
 
-The file src/iceberg/util/checked_cast.h contains code adapted from
-
-https://github.com/apache/arrow/blob/main/cpp/src/arrow/util/checked_cast.h
-
-The file src/iceberg/util/visit_type.h contains code adapted from
-
-https://github.com/apache/arrow/blob/main/cpp/src/arrow/visit_type_inline.h
-
-The file src/iceberg/util/decimal.h contains code adapted from
-
-https://github.com/apache/arrow/blob/main/cpp/src/arrow/util/decimal.h
-
-The file src/iceberg/util/decimal.cc contains code adapted from
+This product includes code from Apache Arrow.
 
-https://github.com/apache/arrow/blob/main/cpp/src/arrow/util/decimal.cc
+* Core utilities:
+  * checked_cast utility in src/iceberg/util/checked_cast.h.
+  * visit_type utility in src/iceberg/util/visit_type.h.
+  * Decimal128 implementation details in src/iceberg/util/decimal files.
+* Build system modules:
+  * cmake_modules/IcebergBuildUtils.cmake.
+  * cmake_modules/IcebergThirdpartyToolchain.cmake.
 
 Copyright: 2016-2025 The Apache Software Foundation.
 Home page: https://arrow.apache.org/
 License: https://www.apache.org/licenses/LICENSE-2.0
 
 --------------------------------------------------------------------------------
-
-3rdparty dependency spdlog is statically linked in certain binary
-distributions. spdlog has the following license:
-
-MIT License
-
-Copyright (c) 2016 Gabi Melman
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-
---------------------------------------------------------------------------------
-
-3rdparty dependency zlib is used by certain binary distributions. zlib has
-the following license:
-
-zlib License
-
-Copyright (c) 1995-2024 Jean-loup Gailly and Mark Adler
-
-This software is provided 'as-is', without any express or implied
-warranty. In no event will the authors be held liable for any damages
-arising from the use of this software.
-
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-
-1. The origin of this software must not be misrepresented; you must not
-   claim that you wrote the original software. If you use this software
-   in a product, an acknowledgment in the product documentation would be
-   appreciated but is not required.
-2. Altered source versions must be plainly marked as such, and must not be
-   misrepresented as being the original software.
-3. This notice may not be removed or altered from any source distribution.
-
-Jean-loup Gailly        Mark Adler
-[email protected]          [email protected]

NOTICE

@@ -3,22 +3,3 @@ Copyright 2024-2025 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).
-
-This product includes code from smhasher
- * MurmurHash3 was written by Austin Appleby, and is placed in the public
- * domain. The author hereby disclaims copyright to this source code.
- * https://github.com/aappleby/smhasher
-
-This product includes code from Apache Arrow
- * Copyright 2016-2025 The Apache Software Foundation
- * https://github.com/apache/arrow
-
-This product includes software developed by Gabi Melman
- * spdlog: Very fast, header-only/compiled, C++ logging library
- * Copyright (c) 2016 Gabi Melman
- * https://github.com/gabime/spdlog
-
-This product includes software developed by Jean-loup Gailly and Mark Adler
- * zlib: A Massively Spiffy Yet Delicately Unobtrusive Compression Library
- * Copyright (c) 1995-2024 Jean-loup Gailly and Mark Adler
- * https://zlib.net/