software/peertube: set npm_config_build_from_source, prevent some check_software errors
setting npm_config_build_from_source tells npm/yarn to build the source packages instead of using pre-built packages.
This was not enough to solve check_software problems with pre-compiled extensions in binary packages such as @lmdb/lmdb-linux-x64 because these packages get installed anyway. For reference the problem is that such packages contain multiple binaries for different libc versions, which causes check_software from software release test to fail differently on different linux versions. To address this, we remove the files that are not used and mark non executable the ones that might be used.