Unexpectedly, my proxy:fcgi stopped working for my PHP 8.1 for my Multi-PHP setup in my MacOS using homebrew. This error appeared 

php -v
dyld[36238]: Library not loaded: /usr/local/opt/libavif/lib/libavif.15.dylib
  Referenced from: <C0D0D41F-85D0-39DA-A030-88CA3164338E> /usr/local/Cellar/gd/2.3.3_5/lib/libgd.3.dylib
  Reason: tried: '/usr/local/opt/libavif/lib/libavif.15.dylib' (no such file).

The solution was to install the gd library.

brew install gd

Or, try reinstalling the gd library.

brew reinstall gd