finish combined abseil/grpc/protobuf migration

[h-vetinari]

Needed to start new migration that'll probably be necessary for tensorflow, see conda-forge/libprotobuf-feedstock#185 / conda-forge/tensorflow-feedstock#329

Biggest issue with this is actually if we're ready to bump the MACOSX_DEPLOYMENT_TARGET globally (it was suggested to include this in the migrator in the context of conda-forge/conda-forge.github.io#1844 resp. #4814)

TODO:

• Rebuild for libabseil20230802_libgrpc157_libprotobuf4234 obake-feedstock#41 (needs new version)
• Rebuild for libabseil20230802_libgrpc157_libprotobuf4234 or-tools-feedstock#48 (needs new version)
• Rebuild for libabseil20230802_libgrpc157_libprotobuf4234 protozfits-feedstock#24
• https://github.com/conda-forge/pyaudi-feedstock (waiting for obake)
• https://github.com/conda-forge/tensorflow-feedstock (attempted here, might skip to 4.24 directly)
• [main] Rebuild for libabseil20230802_libgrpc157_libprotobuf4234 singlejar-feedstock#29 (done despite the migrator showing bot error)

Obsolete (missed the last few migrations already)

• Rebuild for libabseil20230802_libgrpc157_libprotobuf4234 bear-feedstock#39
• Rebuild for libabseil20230802_libgrpc157_libprotobuf4234 mongodb-feedstock#76
• https://github.com/conda-forge/go-cockroach-feedstock
• https://github.com/conda-forge/mysql-connector-python-feedstock
• https://github.com/conda-forge/tomviz-feedstock

Xref #4075

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[h-vetinari]

Biggest issue with this is actually if we're ready to bump the MACOSX_DEPLOYMENT_TARGET globally (it was suggested to include this in the migrator in the context of conda-forge/conda-forge.github.io#1844 resp. #4814)

updated the PR after discussion in that issue.

[h-vetinari]

FYI I plan to merge this and move forward with #4962 on the weekend. Please let me know if anyone has some concerns with that.