style: Allow a blank line at the end of YAML files

[sean-rose]

Description

By default yamllint requires files to end with a newline (docs) but doesn't allow any blank lines at the end of YAML files (docs). This can sometimes be tricky for developers to get exactly right, especially depending on their particular text editor settings (e.g. Slack thread).

This PR relaxes the yamllint configuration to allow one blank line at the end of YAML files to avoid that gotcha.

Related Tickets & Documents

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[akkomar]

question (non-blocking, because I believe you spent more time looking into this than me): wouldn't it be better to add a pre-commit hook to fix end-of-file newlines instead? It would auto-fix the issue and keep EOF handling consistent across all file types (Black already enforces this for Python).

[sean-rose]

wouldn't it be better to add a pre-commit hook to fix end-of-file newlines instead? It would auto-fix the issue and keep EOF handling consistent across all file types (Black already enforces this for Python).

As someone who uses the pre-commit setup that's fine by me, but my impression is not many people are actually using that (though I suppose situations like this could help instigate uptake).

Also, there currently isn't a pre-commit setup in private-bigquery-etl, though that'd probably be a good idea and should be relatively straightforward to do (except for the ones that use bqetl commands).

@scholtzan do you have an opinion on this?