test(e2e): bind bucket.bats S3 client to 127.0.0.1 instead of localhost

`kubectl port-forward service/seaweedfs-s3 -n tenant-root 8333:8333`
binds the listener to 127.0.0.1 only — it has no IPv6 listener. The
runner's getaddrinfo resolves `localhost` to `::1` first, and `mc`
keeps a single connection target across the whole alias, so the
initial `mc alias set` (which only sets credentials, no network I/O)
silently succeeds while the subsequent `mc cp` upload tries
`https://[::1]:8333` and gets immediate `connection refused`. The
test then exits with the misleading bucket-test failure even though
the S3 backend, credentials, and bucket all reconciled correctly.

Use a literal IPv4 address (`127.0.0.1`) for the mc aliases and the
`nc -z` readiness probe so the test no longer depends on the
runner's IPv4/IPv6 resolution policy.

Signed-off-by: Ivan Okhotnikov <ivan.okhotnikov@aenix.io>

hack/e2e-apps/bucket.bats

@@ -45,7 +45,7 @@ EOF
   timeout 30 sh -ec 'until nc -z localhost 8333; do sleep 1; done'
 
   # --- Test readwrite user (admin) ---
-  mc alias set rw-user https://localhost:8333 $ADMIN_ACCESS_KEY $ADMIN_SECRET_KEY --insecure
+  mc alias set rw-user https://127.0.0.1:8333 $ADMIN_ACCESS_KEY $ADMIN_SECRET_KEY --insecure
 
   # Admin can upload
   echo "readwrite test" > /tmp/rw-test.txt
@@ -58,7 +58,7 @@ EOF
   mc cp --insecure rw-user/$BUCKET_NAME/rw-test.txt /tmp/rw-test-download.txt
 
   # --- Test readonly user (viewer) ---
-  mc alias set ro-user https://localhost:8333 $VIEWER_ACCESS_KEY $VIEWER_SECRET_KEY --insecure
+  mc alias set ro-user https://127.0.0.1:8333 $VIEWER_ACCESS_KEY $VIEWER_SECRET_KEY --insecure
 
   # Viewer can list
   mc ls --insecure ro-user/$BUCKET_NAME/rw-test.txt