ci: regenerate the XFS fixture when expected.tsv is also missing

The 'Real XFS deletion fixture (Linux)' step only checked for
disk.img before deciding to skip scripts/make-xfs-real-deletion.sh,
but crates/guara-core/tests/xfs.rs requires both disk.img AND
expected.tsv to exist (img.exists() && tsv.exists()) before it will
run the real-deletion test, panicking with GUARA_REQUIRE_FIXTURES=1
otherwise.

A stale disk.img from an earlier run that failed partway through (for
example the container.privileged: false bug just fixed on the Gitea
runners, where sudo mount -o loop had no capability to succeed)
lingers in the persistent /opt/hostedtoolcache/guara-testdata/ cache
without its matching expected.tsv, so the workflow step kept deciding
there was nothing to do while the test kept failing for the opposite
reason.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VAyr8d7HuAdUGB6aA5xmDD

.gitea/workflows/ci.yml

@@ -67,7 +67,7 @@ jobs:
         if: runner.os == 'Linux'
         continue-on-error: true
         run: |
-          if [ ! -f target/testdata/xfs-real-delete/disk.img ]; then
+          if [ ! -f target/testdata/xfs-real-delete/disk.img ] || [ ! -f target/testdata/xfs-real-delete/expected.tsv ]; then
             sudo scripts/make-xfs-real-deletion.sh
           fi
       - name: Run tests