Disable broken cagg_refresh_cleanup_register test

This fails most of the time and runs into 6 minute timeout
prolonging ci runtimes

Author: svenklemm

tsl/test/isolation/specs/CMakeLists.txt

@@ -50,7 +50,8 @@ if(CMAKE_BUILD_TYPE MATCHES Debug)
     cagg_concurrent_refresh_invalidation_cutting.spec
     cagg_hierarchical_concurrent_refresh.spec
     cagg_incremental_concurrent.spec
-    cagg_refresh_cleanup_register.spec
+#   disabled cause its flaky and takes 6 minutes when failing
+#   cagg_refresh_cleanup_register.spec
     compact_chunk_concurrent.spec
     compression_chunk_race.spec
     direct_compress_copy.spec