fix: Run black on protobuf Python files in CI check

The assert-no-changes.sh script was missing black formatting for
the generated Python protobuf files, causing CI to fail after
commit aa9c561 applied black formatting to those files.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

bin/assert-no-changes.sh

@@ -9,6 +9,7 @@ for proto in $(find ./rbproto -iname '*.proto'); do
 		protoc -I=./rbproto --python_out=./rbproto/python --pyi_out=./rbproto/python ./rbproto/shot.proto
     yarn pbjs ./rbproto/shot.proto --ts ./rbproto/ts/shot.ts
 done
+black rbproto/python
 prettier ./rbproto --write
 
 git ls-files | xargs md5sum > after.txt