CI: enforce newline at EOF and fix existing violations

[arsh118]

Purpose of PR?:

Fixes #

Does this PR introduce a breaking change?

If the changes in this PR are manually verified, list down the scenarios covered::

Additional information for reviewer? :
Mention if this PR is part of any design or a continuation of previous PRs

Does this PR results in some Documentation changes?
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Checklist:

• Bug fix. Fixes #
• New feature (Non-API breaking changes that adds functionality)
• PR Title follows the convention of <type>: <subject>
• Commit has unit tests

[matrss]

Hey! Thanks for the PR.

Unfortunately it doesn't address the issue sufficiently. We have some binary files in the repository that this check also finds, while the rule should only apply to text files.

Could you please explain why the check for the newline works? I get that you are reading out the last byte of each file, but I don't understand why read -r _ exits with non-zero when that byte is not a newline. I couldn't find documentation for this behavior.

The first -f check seems redundant, since git ls-files should already only output file paths. The first read would also mangle some (admittedly very weird) file names containing e.g. backslashes.