chore: upgrade rules_go to 0.49.0

[quartzmo]

• upgrade bazel_gazelle to 0.38.0
• upgrade com_google_protobuf to 25.4
• add rules_proto 6.0.2
• remove -use_generic_streams_experimental
  • fix error: protoc-gen-go-grpc: no such flag -use_generic_streams_experimental

refs: #1554

[noahdietz]

remove -use_generic_streams_experimental

• fix error: protoc-gen-go-grpc: no such flag -use_generic_streams_experimental

We will need to take the "breaking change" introduced by this if we want to remove it. The change applies to our showcase testing stuff, so not that big of a deal tbh.

grpc-go went from a stream client interface, to a Go "generic" type, which apidiff flags as an incompat change in the grpc code we generate on the fly for showcase.

[quartzmo]

@noahdietz You mean we just need to merge this PR in spite of the failing apidiff, correct? Or do you think the merge commit should flag the breaking change with a bang, and that the release notes should mention it?

[codyoss]

@quartzmo have you tried to add this change to googleapis to see if it is compatible there?

[quartzmo]

I ran bazelisk clean --expunge && bazelisk build //google/cloud/asset/v1:asset_go_gapic locally against latest googleapis with googleapis/WORKSPACE pointed at local branch for this PR, is that what you mean?

[quartzmo]

@noahdietz My local protoc was outdated, which is why I got the error no such flag -use_generic_streams_experimental and mistakenly assumed the flag had been removed. Restored.

[codyoss]

@quartzmo I would try to build the whole package(so other langs too). The reason I ask is because our workspace in googleapis explicitly sets the version of some of these deps. But I think this change would cause them to raise:

• https://github.com/googleapis/googleapis/blob/6a474b31c53cc1797710206824a17b364a835d2d/WORKSPACE#L152
• https://github.com/googleapis/googleapis/blob/6a474b31c53cc1797710206824a17b364a835d2d/WORKSPACE#L111

[quartzmo]

@codyoss Thanks for pointing that out. I reverted the updates to com_google_protobuf and bazel_gazelle, leaving only the io_bazel_rules_go update.