graphics/qgis-ltr: upgrade 3.4.7 -> 3.4.11
- Build with ports clang default version
- Add astro/gpsbabel as dependency
- Update several Python dependencies
- Add devel/py-geojson, devel/py-nbformat, math/py-networkx, graphics/py-pillow, graphics/py-scikit-image, and devel/py-shapely for Python extension
- Add -DCMAKE_POLICY_DEFAULT_CMP0056:STRING=NEW
PR: 240105
Submitted by: Rainer Hurling <rhurlin@gwdg.de> (maintainer)