Minor style cleanup, using f-strings

[brews]

Minor update converting % string formatting to use newer recommended f-string formatting. It's now a best practice. Should be easier to read.

This should have no change on package functionality.

This also bumps ruff to 0.8.x, which recommended the change when Dependabot tried to bump it in #348.

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 2 lines in your changes missing coverage. Please review.

Project coverage is 68.91%. Comparing base (44cc7f7) to head (5cd83b2).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/dscim/utils/rff.py	33.33%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #351   +/-   ##
=======================================
  Coverage   68.91%   68.91%           
=======================================
  Files          15       15           
  Lines        1750     1750           
=======================================
  Hits         1206     1206           
  Misses        544      544           

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[brews]

@JMGilbert tapping you for review on this, but I know you're busy. Appreciate your help. This should not take more than 5 minutes. It's a very small update to code syntax. Ruff was suggesting a change to keep up with Python best practices as the language evolves.

[JMGilbert]

I'm surprised we had and % strings left. Happy to make the full official switch to f strings!