chore(infra): audit workflows, scripts (#33055)

Mostly adding a descriptive frontmatter to workflow files. Also address
some formatting and outdated artifacts

No functional changes outside of
[d5457c3](d5457c39ee),
[90708a0](90708a0d99),
and
[338c82d](338c82d21e)

.github/scripts/prep_api_docs_build.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-"""Script to sync libraries from various repositories into the main langchain repository."""
+"""Sync libraries from various repositories into this monorepo."""
 
 import os
 import shutil