Fixes <https://issues.guix.gnu.org/61853>.
Fixes a regression introduced in
68380db4c4, whereby the tarball's root
entry is now read-only, due to the creation of "profile-directory" in
the store.
* tests/guix-pack.sh: Remove and recreate $test_directory before
transformation option test.
* tests/guix-pack-relocatable.sh: Add "chmod +w $test_directory" lines
before attempts to write to it.