Drop GCC11 from ci

Which make the workaround for https://gcc.gnu.org/PR89074 and P1004R2
`constexpr` `std::vector` unnecessary which `constexpr` test coverage
enabled.

Author: frederick-vs-ja

.github/workflows/ci.yml

@@ -16,7 +16,6 @@ jobs:
           - {name: "Ubuntu Clang 18", os: ubuntu-24.04, toolchain: "clang-18", clang_version: 18, installed_clang_version: 17, cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "}
           # Note: clang-19 + Asan setup causes errors on some platforms. Temporary skip some checks via .asan_options.
           - {name: "Ubuntu Clang 19", os: ubuntu-24.04, toolchain: "clang-19", clang_version: 19, installed_clang_version: 17, cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" ", asan_options: "new_delete_type_mismatch=0"}
-          - {name: "Ubuntu GCC 11", os: ubuntu-24.04, toolchain: "gcc-11",  cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "}
           - {name: "Ubuntu GCC 12", os: ubuntu-24.04, toolchain: "gcc-12",  cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "}
           - {name: "Ubuntu GCC 13", os: ubuntu-24.04, toolchain: "gcc-13",  cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "}
           - {name: "Ubuntu GCC 14", os: ubuntu-24.04, toolchain: "gcc-14", cmake_args: "-G \"Ninja Multi-Config\" -DCMAKE_CONFIGURATION_TYPES=\"RelWithDebInfo;Asan\" "}