[PyCon.de sprints] Fix various pylint finds

[snordhausen]

Remove re-imports, unused variables, implicit string concatenation, overly complex assignment.

Checklist

• Added a news entry
• Regenerated schema JSON if schema altered (python -m conda_smithy.schema)

[jaimergp]

Thanks! Just one little change about those imports. We are already importing a few things from vsts so no need to keep any inlined.

[dbast]

Can the pylint rules which found those things be activated via the rules list at https://github.com/conda-forge/conda-smithy/blob/main/pyproject.toml#L46?

[snordhausen]

@dbast I'll look into that and include the rules for #2520, too.

[snordhausen]

@dbast
For unused variables that are created as part of a loop, theres B007`. But that rule will require some additional changes, so I'll put it into a separate PR once this one is merged.

For the re-imports, pylint's W0404 (reimported) seems to have no ruff equivalent. There's only PLC0415 for imports not at the top level. But this is actually used a lot in cli.py (I assume to emulate lazy loading).

For the .format() calls that should have been f-strings in #2520, I checked with some other sprint participants and ruff seems to have no rule to catch those specific cases.

So in summary, ruff seems to be missing some rules to catch these specific issues that were detected by pylint.