Log Message:
{py-,}protobuf: update to {3,4}.21.2

2022-05-27 version 21.1 (C++/Java/Python/PHP/Objective-C/C#/Ruby)

  C++
  * cmake: Revert "Fix cmake install targets (#9822)" (#10060)
  * Remove Abseil dependency from CMake build (#10056)

  Python
  * Update python wheel metadata with more information incl. required python \ 
version (#10058)
  * Fix segmentation fault when instantiating field via repeated field \ 
assignment (#10066)

2022-05-25 version 21.0 (C++/Java/Python/PHP/Objective-C/C#/Ruby)

  C++
  * cmake: Call get_filename_component() with DIRECTORY mode instead of PATH \ 
mode (#9614)
  * Escape GetObject macro inside protoc-generated code (#9739)
  * Update CMake configuration to add a dependency on Abseil (#9793)
  * Fix cmake install targets (#9822)
  * Use __constinit only in GCC 12.2 and up (#9936)

  Python
  * Increment python major version to 4 in version.json for python upb (#9926)
  * The C extension module for Python has been rewritten to use the upb library.
    This is expected to deliver significant performance benefits, especially when
    parsing large payloads.  There are some minor breaking changes, but these
    should not impact most users.  For more information see:
    \ 
https://developers.google.com/protocol-buffers/docs/news/2022-05-06#python-updates
  * Fixed win32 build and fixed str(message) on all Windows platforms. (#9976)
  * The binary wheel for macOS now supports Apple silicon.

2022-05-19 version 21.0-rc2(C++/Java/Python/PHP/Objective-C/C#/Ruby)

  Python
  * Fix windows builds
  * Throw more helpful error if generated code is out of date
  * Fixed two reference leaks

2022-05-10 version 21.0-rc1 (C++/Java/Python/PHP/Objective-C/C#/Ruby)

  C++
  * Rename main cmake/CMakeLists.txt to CMakeLists.txt (#9603)
  * avoid allocating memory if all extension are cleared (#9345)
  * cmake: Call get_filename_component() with DIRECTORY mode instead of PATH \ 
mode (#9614)
  * Escape GetObject macro inside protoc-generated code (#9739)
  * Update CMake configuration to add a dependency on Abseil (#9793)
  * Use __constinit only in GCC 12.2 and up (#9936)
  * Refactor generated message class layout
  * Optimize tokenizer ParseInteger by removing division
  * Reserve exactly the right amount of capacity in ExtensionSet::MergeFrom
  * Parse FLT_MAX correctly when represented in JSON

  Python
  * Increment python major version to 4 in version.json for python upb (#9926)
  * The C extension module for Python has been rewritten to use the upb library.
    This is expected to deliver significant performance benefits, especially when
    parsing large payloads.  There are some minor breaking changes, but these
    should not impact most users.  For more information see:
    \ 
https://developers.google.com/protocol-buffers/docs/news/2022-05-06#python-updates
  * Due to the breaking changes for Python, the major version number for Python
    has been incremented.
  * The binary wheel for macOS now supports Apple silicon.

  Compiler
  * Protoc outputs the list of suggested field numbers when invalid field
    numbers are specified in the .proto file.
  * Require package names to be less than 512 bytes in length