[!812] [cmake][bugfix] Use install(PROGRAMS...) signature to install executable scripts

Merge branch 'feature/install-scripts-executable' into 'master'

ref:core/dune-common> CMake does not preserve file permissions when installing files. In order to get executable scripts installed, the install(PROGRAMS...) signature needs to be used instead of install(FILES...).

See merge request core/dune-common!812

(cherry picked from commit cc5ed571)

ee4cef6d [cmake][bugfix] Use install(PROGRAMS...) signature to install executable scripts

enabled an automatic merge when the pipeline for e1c92f23 succeeds

merged

mentioned in commit 20a8172d