resolving minor linter issues

[TimmRuppert]

Very minor code cosmetics like:

• f-strings without any placeholders
• unused imports

[pmai]

Since they mostly apply to non-osirules checker code, I'd retarget that to main and handle separately - the osirules relevant two changes are now incorporated in the osirules PR.

[TimmRuppert]

Since they mostly apply to non-osirules checker code, I'd retarget that to main and handle separately - the osirules relevant two changes are now incorporated in the osirules PR.

I just re-targeted to main and removed changes related to #6