Fix CI action autotools-macos for MacPorts
Fix CI action autotools-macos for MacPorts

Remove the existing installation of Homebrew for tests with MacPorts.
Allow also to run the CI on demand manually.

Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

amitdo/tesseract,tesseract-ocr/tesseract,stweil/tesseract,stweil/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,stweil/tesseract,stweil/tesseract,stweil/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract