setup-hooks/separate-debug-info.sh: don't inhibit strip hook

Before the change separate-debug-info.sh did the stripping itself.
This scheme has a few problems:
1. Stripping happens only on ELF files. *.a and *.o files are skipped.
   Derivations have to do it manually. Usually incorrectly
   as they don't run $RANLIB (true for `glibc` and `musl`).
2. Stripping happens on all paths. Ideally only `stripDebugList` paths
   should be considered.
3. Host strip is called on Target files.

This change offloads stripping logic to strip hook. This strips more
files for `glibc` and `musl`. Now we can remove most $STRIP calls
from individual derivations.

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

pkgs/development/interpreters/python/cpython/default.nix

@@ -430,11 +430,6 @@ in with passthru; stdenv.mkDerivation {
     # This allows build Python to import host Python's sysconfigdata
     mkdir -p "$out/${sitePackages}"
     ln -s "$out/lib/${libPrefix}/"_sysconfigdata*.py "$out/${sitePackages}/"
-
-    # debug info can't be separated from a static library and would otherwise be
-    # left in place by a separateDebugInfo build. force its removal here to save
-    # space in output.
-    $STRIP -S $out/lib/${libPrefix}/config-*/libpython*.a || true
     '' + optionalString stripConfig ''
     rm -R $out/bin/python*-config $out/lib/python*/config-*
     '' + optionalString stripIdlelib ''