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some formatting and outdated artifacts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](https://github.com/langchain-ai/langchain/pull/33055/commits/d5457c39eeab30786d97d7447ddabcc7e9c3afe4),
[90708a0](https://github.com/langchain-ai/langchain/pull/33055/commits/90708a0d99613cc4e1ff67da82a5525839682b6d),
and
[338c82d](https://github.com/langchain-ai/langchain/pull/33055/commits/338c82d21e894e07bc85fea994ba0a3e9ac57db5)