2.1.1-beta2: 2.1.1-Beta2

Changes since 2.1.0-Beta1:
- Fix missing exported z_size_t type in zlib.h (zlib-compat mode).
- Fix two Coverity warnings
- Fix CMake GNUInstallDirs usage
- Configure/CMake improvements for compilers with early AVX512-VNNI support (GCC8.0 etc)
- Microptimalization for AVX512 implementation of CRC32
- Optimized deflate_rle compression, also added related test and benchmark.
- Add testing of file_compress/file_uncompress in minigzip/minideflate
- Add emulated RISC-V to CI test workflow
- Add deflate_fast to switchlevels test
- Fix abicheck CI test was not ignoring version string
- Fix MinGW CI test, broken by Github Actions VM image updates