test(cz_customize): add missing YAML configuration file tests

[AdrianDC]

Partial rebase of #1207 for tests commits made last summer.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (v4-9-2@69d32cf). Learn more about missing BASE report.

Additional details and impacted files

@@ Coverage Diff @@## v4-9-2 #1516 +/- ##
=========================================
Coverage ? 98.71% =========================================
Files ? 60 Lines ? 2655 Branches ? 0 =========================================
Hits ? 2621 Misses ? 34 Partials ? 0 

Flag	Coverage Δ
unittests	98.71% <ø> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Lee-W]

same here

[AdrianDC]

Uniformization of a reference examples that uses both quoting styles

[Lee-W]

idea looks good. left some nitpicks

[AdrianDC]

Rebased from last year's PR, to update towards 4.9.1+adriandc.20250914
for pre-commit-crocodile 8.0.0 (prek becoming default btw).

Feel free to edit the PR or cherry-pick at will.

---

For the record, I'm not a fan of pinning to a patched & customized fork for so long,
blocking my users + coworkers on a specific version of commitizen-tools that I rebase 2-3 times a year,
including now v5-moved fixes and questions features, but works fine since August 2024.