Don't use bazel to run tools/add_module.py in bcr fork

BCR depends on rules_python, which can conflict with the version in
the module that is being added

.github/workflows/publish-rabbitmq-bcr.yml

@@ -55,7 +55,8 @@ jobs:
 
         jq '.' ${MODULE_NAME}.json
 
-        bazel run //tools:add_module -- \
+        pip install -r tools/requirements_lock.txt
+        python3 tools/add_module.py \
           --input=${MODULE_NAME}.json
 
         git diff