tests: Move the old vmstate-static-checker files to tests/data/

All other test data resides in tests/data/, so let's move the dump
files here, too.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20250912100755.316518-2-thuth@redhat.com>

MAINTAINERS

@@ -3613,7 +3613,7 @@ F: migration/
 F: scripts/vmstate-static-checker.py
 F: tests/functional/migration.py
 F: tests/functional/*/*migration.py
-F: tests/vmstate-static-checker-data/
+F: tests/data/vmstate-static-checker/
 F: tests/qtest/migration/
 F: tests/qtest/migration-*
 F: docs/devel/migration/