Disable rules_python in Downstream (#2365)

Disabled due to reason :
https://github.com/bazel-contrib/rules_python/issues/3122,
https://github.com/bazel-contrib/rules_python/issues/2954
diff --git a/buildkite/bazelci.py b/buildkite/bazelci.py
index ce75af2..297f4a5 100755
--- a/buildkite/bazelci.py
+++ b/buildkite/bazelci.py
@@ -232,6 +232,7 @@
     "rules_python": {
         "git_repository": "https://github.com/bazel-contrib/rules_python.git",
         "pipeline_slug": "rules-python-python",
+        "disabled_reason": "https://github.com/bazel-contrib/rules_python/issues/2954, https://github.com/bazel-contrib/rules_python/issues/3122",
     },
     "rules_testing": {
         "git_repository": "https://github.com/bazelbuild/rules_testing.git",