graphics/qgis: Update to 3.14.15
- Update to 3.14.15
- Remove files/patch-src_core_CMakeLists.txt (upstreamed) [1]
- Prepare for PyQt5 and Sip5 [2]
[1] https://github.com/qgis/QGIS/pull/38103
[2] Upstream PR https://github.com/qgis/QGIS/pull/37901 (included in 3.14.15) and https://github.com/qgis/QGIS/pull/37842 (patches taken from commits)
PR: 248783
Approved by: Rainer Hurling (maintainer)