refactor!: Remove deprecated StaticFileConfig

[provinzkraut]

Removes the deprecated static_files_config and friends.

(please don't merge yet, this needs some docs and a better description 🙂)

[JacobCoffee]

Could you potentially wait and rebase against main or #3358 before doing remaining docs-related tings? no big deal if not

[peterschutt]

I've started a "What's new in 3.0" document in #3297 (also needing review 😉) Disregard, this is in #3324

[codecov]

Codecov Report

Attention: Patch coverage is 98.63014% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 98.24%. Comparing base (622b53b) to head (e69c376).

❗ Current head e69c376 differs from pull request most recent head 86501dc. Consider uploading reports for the commit 86501dc to get more accurate results

Files	Patch %	Lines
litestar/static_files.py	98.57%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             v3.0    #3357      +/-   ##
==========================================
- Coverage   98.28%   98.24%   -0.04%     
==========================================
  Files         323      321       -2     
  Lines       14773    14687      -86     
  Branches     2345     2334      -11     
==========================================
- Hits        14519    14429      -90     
  Misses        116      116              
- Partials      138      142       +4     

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