Fix globbing in tarball script for releases (#1378)

scripts/create_tarball.sh

@@ -39,12 +39,12 @@ git checkout "$CHECKOUT"
 git submodule init
 git submodule update
 
-# remove all version control files but not the .git directories themselves
-rm -vrf -- **/.git/*
-
-# remove main .git, only submodule .gits are still present
+# remove main .git
 rm -vrf .git
 
+# wipe .git submodule files
+find -type f -name .git | xargs truncate -s 0
+
 # create tar ball
 cd ..
 tar vcfz "$OUT_TARBALL" $REPO_NAME