graphics/qgis-ltr: Update to 3.10.10

This is a minor update for QGIS from 3.10.9 to 3.10.10. It fixes several problems and brings some new features.

• Enabling OpenCL features
• Update some Python deps under BUILD_DEPENDS
• Add devel/protobuf in LIB_DEPENDS
• Reorder USES part
• Delete pycache via post-install target
• Update distinfo

Approved by: tcberner (mentor)
Relnotes: https://github.com/qgis/QGIS/compare/final-3_10_9...final-3_10_10
Differential Revision: https://reviews.freebsd.org/D26563