🚨 first iteration of ruff check error fixes

[jorenham]

1260    RUF036  [ ] none-not-at-end-of-union
 594    ANN001  [ ] missing-type-function-argument
 164    ANN201  [ ] missing-return-type-undocumented-public-function
  62    ANN204  [ ] missing-return-type-special-method
  55    ICN003  [ ] banned-import-from
  48    SLF001  [ ] private-member-access
  39    ERA001  [*] commented-out-code
  37    TD002   [ ] missing-todo-author
  37    PLR0124 [ ] comparison-with-itself
  36    ANN202  [ ] missing-return-type-private-function
  27    PYI019  [*] custom-type-var-return-type
  21    B015    [ ] useless-comparison
  17    FBT003  [ ] boolean-positional-value-in-call
  15    ANN003  [ ] missing-type-kwargs
  15    PYI017  [ ] complex-assignment-in-stub
  14    ANN002  [ ] missing-type-args
  12    B018    [ ] useless-expression
   9    F821    [ ] undefined-name
   8    PYI052  [ ] unannotated-assignment-in-stub
   6    PYI018  [ ] unused-private-type-var
   5    PTH123  [ ] builtin-open
   5    PLC0105 [ ] type-name-incorrect-variance
   5    PLC2801 [ ] unnecessary-dunder-call
   4    PYI063  [ ] pep484-style-positional-only-parameter
   3    PYI001  [ ] unprefixed-type-param
   3    PT009   [ ] pytest-unittest-assertion
   3    F811    [ ] redefined-while-unused
   2    PYI034  [*] non-self-return-type
   1    ANN206  [ ] missing-return-type-class-method
   1    S404    [ ] suspicious-subprocess-import
   1    E402    [ ] module-import-not-at-top-of-file
   1    PGH003  [ ] blanket-type-ignore
   1    RUF039  [ ] unraw-re-pattern
[*] fixable with `ruff check --fix`