* refactor(release): switch release integrity to be dynamic
This matches rules_py as documented by
https://blog.aspect.build/releasing-bazel-rulesets-rust
It has the benefit that developers no longer get yelled at to vendor some updated integrity hashes into bazel-lib every time they touch the Go sources.
* refactor: echo should produce trailing newline
* chore: bump action-gh-release to avoid Node 16 warning
* chore: update test that is sensitive to compilation mode
We now only use --compilation_mode=opt when cutting a release
David Zbarsky