Upgrade to abseil-cpp 20240722.0

[HannahShiSFB]

Abseil-cpp source snapshot from release tag 20240722.0

Removed all test and benchmark files:

rm -rf `find absl/ -name "*_test.cc"`
rm -rf `find absl/ -name "*_benchmark.cc"`
rm absl/status/internal/status_matchers.*
rm -rf absl/time/internal/cctz/testdata
rm -rf `find absl/ -name "BUILD.bazel"`
rm -rf `find absl/ -name "CMakeLists.txt"`
rm -rf absl/copts

For gRPC dependency starting form 1.68.x grpc/grpc#37543

[HannahShiSFB]

CC: @paulb777 @sampajano

[paulb777]

Is it feasible to remove the files necessary to fix the 600+ build warnings? https://github.com/firebase/abseil-cpp-SwiftPM/actions/runs/11714366860/job/32628923274#step:6:817

[HannahShiSFB]

Majority of them are timezon data, which I don't know whether it's safe to remove them.
There are also some inc files cannot be removed.
I can remove the bazel and cmake build files.

[paulb777]

If SPM isn't finding the timezone data, they're not being built. If they're needed, they should be included in a resources specification in the Package.swift.

[paulb777]

LGTM Thanks!

Is it ready to merge and tag?

[HannahShiSFB]

Yes, please go ahead, thanks.

[paulb777]

Merged, tagged, and created a GitHub release - https://github.com/firebase/abseil-cpp-SwiftPM/releases/tag/0.20240722.0