[docs] Revert extra changes from PR 17848 (#18003)

## Summary

1. Revert https://github.com/openai/codex/pull/17848 so the Bazel and
`BUILD` file changes leave `main`.
2. Prepare for a narrower follow up that restores only `SECURITY.md`.

## Validation

1. Reviewed the revert diff against `main`.
2. Ran a clean diff check before push.

.github/workflows/bazel.yml

@@ -94,7 +94,7 @@ jobs:
             "${bazel_wrapper_args[@]}" \
             -- \
             test \
-            --test_tag_filters=-argument-comment-lint,-flaky \
+            --test_tag_filters=-argument-comment-lint \
             --test_verbose_timeout_warnings \
             --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
             -- \