Add PHP8.2 linting

[ChristophWurst]

Ref nextcloud/groupware#40

[codecov]

Codecov Report

Merging #4249 (dcfdd90) into main (45267ca) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               main    #4249   +/-   ##
=========================================
  Coverage     29.61%   29.61%           
  Complexity      330      330           
=========================================
  Files           220      220           
  Lines          7638     7638           
  Branches       1008     1008           
=========================================
  Hits           2262     2262           
  Misses         5376     5376           

Flag	Coverage Δ
javascript	20.69% <ø> (ø)
php	68.75% <ø> (ø)

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