[CI:DOCS] Add pre-commit (app) hook to check IMGSFX

[cevich]

Intended for use by the pre-commit app, this hook keeps track of all IMG_SFX values pushed, failing when any duplicate is found. In the case of pushing to PRs that don't build CI VM images, the hook failure must be manually bypassed. Example .pre-commit-config.yaml:

---
repos:
  - repo: https://github.com/containers/automation_images.git
    rev: <tag or commit sha>
    hooks:
      - id: check-imgsfx

[cevich]

Manually tested with:

pre-commit try-repo . check-imgsfx --verbose --all-files --hook-stage pre-push

Correctly throws error:

Check IMGSFX for accidental reuse........................................Failed
- hook id: check-imgsfx
- duration: 0s
- exit code: 1

FATAL: 20240620t153000z-f40f39d13 has already been used
Please rerun 'make IMG_SFX'

If I then make IMG_SFX and stage it, running the same command returns:

Check IMGSFX for accidental reuse........................................Passed
- hook id: check-imgsfx
- duration: 0s

[cevich]

force-push: Renamed all IMGSFX references to IMG_SFX.

[cevich]

@edsantiago PTAL, even if you don't use the pre-commit app, I'd appreciate a quick look-through for any typos I may have made.

After this merges, my intention is to open a followup with an example .pre-commit-config.yaml file specific to this repo. In addition to your neat IMG_SFX check, it will also validates yaml, EOF, trailing whitespace, shellcheck, and a few more. But I need a commit-id on main to reference for the new check-imgsfx.

[edsantiago]

pre-commit looks intriguing, thanks for the pointer. I can't verify the config. Some feedback on the sh part.

[cevich]

Force-push: Remove use of $HOME based storage of history. Add intended use/purpose comment block to script.

@edsantiago this is ready for final review/merging. I'll start working on a followup PR to add an example pre-commit configuration file.