chore: prevent renovate-bot from updating psycopg2-binary version (#465)

Currently, renovate-bot creates PRs like
#464,
which are updating the psycopg2-binary package's version from 2.9.9 to
2.9.10 for Python 3.9 and Darwin.

We don't want this update to happen. So setting the version to `<2.9.10`
to check if renovate-bot prevents changing this.

Author: rhatgadkar-goog

requirements-test.txt

@@ -6,8 +6,8 @@ pg8000==1.31.2
 # It is supported for macos-12 runner:
 # https://github.com/psycopg/psycopg2/issues/1737. But macos-12 runner is
 # deprecated: https://github.com/actions/runner-images/issues/10721. So we
-# install psycopg 2.9.9 on Python 3.9 for macos-latest runner.
-psycopg2-binary==2.9.9; python_version == "3.9" and sys_platform == "darwin" 
+# install psycopg <2.9.10 on Python 3.9 for macos-latest runner.
+psycopg2-binary<2.9.10; python_version == "3.9" and sys_platform == "darwin"
 psycopg2-binary==2.9.10; python_version != "3.9" or sys_platform != "darwin"
 
 pytest==8.4.1