Add bufbuild/buf to all-repos.yaml

[wwuck]

https://github.com/bufbuild/buf has included some pre-commit hooks

my new repository:

• [x] is added to the bottom or with existing repos from the same account
• [x] contains a license
• [x] is not language: system, language: script, language: docker, or language: docker_image
• [x] does not contain "pre-commit" in the name

[asottile]

pass_filenames: false is usually wrong and results in always running everything always

[wwuck]

Thanks for the review. I'll open a bug report on their repository.

[asottile]

hi! thanks for the contribution but I'm actually removing this list in favor of a smaller, more manually-curated list of tools -- see #978 for more details