chore: partial release script

[suztomo]

partial_release.py to take "bump-snapshot-version" as argument. These script created a change in #11804.

To create release versions of the modules

~/google-cloud-java$ python3 .github/release/partial_release.py bump-released-version --artifact-ids=google-cloud-java,google-cloud-asset --version-type=patch
~/google-cloud-java$ cd java-asset
~/google-cloud-java/java-asset$ ../generation/apply_versions.sh ../versions.txt released

To create SNAPSHOT versions for the released modules

~/google-cloud-java$ python3 .github/release/partial_release.py bump-snapshot-version --artifact-ids=google-cloud-java,google-cloud-asset
~/google-cloud-java$ ./generation/apply_versions.sh ./versions.txt current