actions: feature: compression: do not hardcode the log path

The log path depends on the previous actions run and may not always
be 01/1.log.zst. Assuming it is makes this test fragile as it is
influenced by which previous tests are run and what they do.

actions/feature-logs-compression/run.sh

@@ -5,4 +5,11 @@ set -e
 source $FEATURE_DIR/../../lib/lib.sh
 source $FEATURE_DIR/../../forgejo/fixtures.sh
 
-fixture_get_one_path local data/actions_log/root/example-echo/01/1.log.zst
+if ! fixture_get_one_path local data/actions_log/root/example-echo | grep --quiet log.zst; then
+    (
+        cd $DIR/forgejo-work-path
+        find data
+    )
+    echo expected a single log.zst file in data/actions_log/root/example-echo
+    exit 1
+fi