math/saga: Update to 8.1.3

Bug fix release with some new features and enhancements

• imagery_tools/sentinel_2_scene_import, level-2 related options and support for latest meta file changes
• fixes for climate_tools/evapotranspiration and climate_tools/bioclimatic_vars
• saga_api/table_io: improved text table
• fix pj_georeference/georef_with_coordinate_grids
• saga_gui: point clouds, color adjustment

Changelog: https://sourceforge.net/p/saga-gis/wiki/Changelog%208.1.2/attachment/changelog_saga_8.1.2.txt
Changelog: https://sourceforge.net/p/saga-gis/wiki/Changelog%208.1.3/attachment/changelog_saga_8.1.3.txt

Reported by: portscout, Repology
MFH: 2022Q1

(cherry picked from commit 8a76d5e7525a9ee5305215a1f46fb1f3869d174f)