address review feedback. Changelog entry. Remove setting policies that are the default with 3.16

Author: dbarker

CHANGELOG.md

@@ -30,6 +30,11 @@ Increment the:
 * [SDK] View should not have a unit
   [#3552](https://github.com/open-telemetry/opentelemetry-cpp/pull/3552)
 
+Important changes:
+
+* [CMAKE] Upgrade CMake minimum version to 3.16
+  [#3599](https://github.com/open-telemetry/opentelemetry-cpp/pull/3599)
+
 Breaking changes:
 
 * [SDK] View should not have a unit

CMakeLists.txt

@@ -3,22 +3,6 @@
 
 cmake_minimum_required(VERSION 3.16)
 
-# See https://cmake.org/cmake/help/latest/policy/CMP0074.html required by
-# certain version of zlib which CURL depends on.
-if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.12")
-  cmake_policy(SET CMP0074 NEW)
-endif()
-
-# Allow to use normal variable for option()
-if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13")
-  cmake_policy(SET CMP0077 NEW)
-endif()
-
-# Prefer CMAKE_MSVC_RUNTIME_LIBRARY if possible
-if(POLICY CMP0091)
-  cmake_policy(SET CMP0091 NEW)
-endif()
-
 if(POLICY CMP0092)
   # https://cmake.org/cmake/help/latest/policy/CMP0092.html#policy:CMP0092 Make
   # sure the /W3 is not removed from CMAKE_CXX_FLAGS since CMake 3.15