🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Author: gcf-owl-bot[bot]

MANIFEST.in

@@ -17,7 +17,7 @@
 # Generated by synthtool. DO NOT EDIT!
 include README.rst LICENSE
 recursive-include third_party/bigframes_vendored *
-recursive-include bigframes *.json *.proto *.js py.typed
+recursive-include bigframes *.json *.proto *.js *.css py.typed
 recursive-include tests *
 global-exclude *.py[co]
 global-exclude __pycache__