Migrate Linux ARM64 workers to Rocky Linux 8 GCE workers

[fweikert]

Currently we have two Linux ARM64 machines for building Bazel binaries, both of which will be turned down soon.

We should use GCE VMs instead to support Linux ARM64, which would also allow us to scale the fleet to a size that's sufficient for actually running tests.

Moreover, the current workers run CentOS 7, which has been EOL for almost a year. We should look into a replacement (such as Rocky Linux 8).

[fweikert]

Next steps:

• Change publish binary pipeline to publish Rocky Linux 8 binaries (both x86_64 and ARM64)
• Increase GCE quota and Linux ARM64 instance group size
• Migrate release pipeline from CentOS to Rocky Linux
• Migrate testing pipelines from CentOS to Rocky Linux
• Stop Buildkite agent on old ARM64 machines
• Rename arm64_v2 queue to arm64 (requires building new GCE images)