Pass --literally to hash-object when making tree

This is needed on some Git versions. It seems it was not needed
on older versions, even though their git-fsck detected the unusual
filenames when run. It is supported even on those older versions,
so the script should still run on them.

Author: EliahKagan

gix-worktree/tests/fixtures/make_traverse_dotgit_slashes.sh

@@ -22,7 +22,7 @@ printf '%s' "$blob_hash" | xxd -r -p >blob-hash-bytes
 tree_hash="$(
     printf '%s %s\0' "$filemode" "$filename" |
     cat - blob-hash-bytes |
-    git hash-object -t tree -w --stdin
+    git hash-object -t tree -w --stdin --literally
 )"
 
 rm blob-hash-bytes