check/build-protos doesn't work anymore

[balopat]

Description of the issue

check/build-protos doesn't work, due to cirq-google/.. path having a dash in the name :(
We need to figure out how to get around this.

It is not urgent, as TFQ is the only user for this, and there we strip that prefix, so it doesn't cause issues during the bazel build. However, it is a bit ugly that we can't run check/build-protos ourselves. It also doesn't update the protos correctly - like dev_tools/build-protos.sh does...maybe we should just get rid of it?

[dabacon]

Curious if there was a reason for the hyphen in the filename naming? Was planning on following a similar pattern in another project, and am leaning towards using underscore, but was curious if there was some strange packaging reason to not do this.

[balopat]

I just simply wanted to follow the pypi package name e.g. the cirq-google pypi package offers the cirq_google namespace. The hypen in the filenames is a bazel issue - more info at bazelbuild/bazel#6841.

[pavoljuhas]

resolved by #6747