Merge pull request #34611 from peterhoeg/p/descent

descent 1 & 2: use assets from gog.com with the dxx-rebirth project

pkgs/build-support/setup-hooks/gog-unpack.sh

@@ -0,0 +1,11 @@
+unpackPhase="unpackGog"
+
+unpackGog() {
+    runHook preUnpackGog
+
+    innoextract --silent --extract --exclude-temp "${src}"
+
+    find . -depth -print -execdir rename -f 'y/A-Z/a-z/' '{}' \;
+
+    runHook postUnpackGog
+}