macdeployqt kept /opt/homebrew paths (e.g. libbrotlicommon's install id).
Rewrite them to @rpath/libX.dylib, copying the library into Frameworks
if needed, over 3 passes to handle chained dependencies.
Recent Homebrew bottles (brotli, webp, sharpyuv) reference their deps as
@rpath/libX.dylib, which macdeployqt skips. Copy them from /opt/homebrew/lib
into Contents/Frameworks after macdeployqt, and abort if any @rpath or
/opt/homebrew reference remains unresolved. Drop the ineffective -libpath.
lang1/ was a leftover from the pre-Qt6 translation pipeline.
Qt6/CMake now produces all .qm files directly into lang/, which
is already copied above, making this step dead code.
Laurent Trinques