feat: add shellcheck

[rwaffen]

fixes: #25

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[rwaffen]

that doesn't look correct to me :(

fatal: Invalid revision range 946875d1caf251c059f951827f592e38cb182fbb..3de9279033bee9f090a8c98b86894db031f38d63


:::::::::::::::::::::
::: Used Versions :::
:::::::::::::::::::::

ShellCheck: 0.9.0
csutils: 3.4.0


:::::::::::::::::::::::::::::::
::: Differential ShellCheck :::
:::::::::::::::::::::::::::::::

📜 List of shell scripts for scanning

fatal: unable to read tree (946875d1caf[25](https://github.com/voxpupuli/container-semantic-release/actions/runs/11495015833/job/31993635136?pr=33#step:4:26)1c059f951827f592e38cb182fbb)
fatal: unable to read tree (946875d1caf251c059f9518[27](https://github.com/voxpupuli/container-semantic-release/actions/runs/11495015833/job/31993635136?pr=33#step:4:28)f592e38cb182fbb)
ℹ️ No Fixes!

error: pathspec '-' did not match any file(s) known to git
No stash entries found.
🥳 No defects added. Yay!

✅ SARIF report was successfully uploaded to GitHub

[rwaffen]

ah okay, i have no scripts in the change, so nothing is checked... 🤔