Cleanup Bazel workarounds for gRPC and `apple_rules`

[coryan]

gRPC 1.60.x does not compile out of the box with Bazel v7. Bazel v7 requires a newer version of apple_rules than what gRPC uses.

We can override the version of apple_rules, but that requires some careful initialization of the C++ toolchain.

Alternatively, it would be nice if gRPC did not require these rules when compiling only C++ targets.

None of these things are true now, but once either becomes true we can remove the code overriding and initializing apple_rules from our project.

[scotthart]

Need to check if gRPC has resolved their portion of this issue.

[jinseopkim0]

From https://grpc.github.io/grpc/core/md_doc_bazel_support.html:

Supported Versions
gRPC supports building with the latest stable release of Bazel, as well as the previous major version release for at least 6 months after it transitions into maintenance mode. This is consistent with the supported build systems of the Google Foundational C++ Support Policy. However individual releases may have a broader compatibility range. The currently supported versions are captured by the following list:

8.0.1
7.4.1