Added google-cloud-core to known list (#2826)

## Changes
Added google-cloud-core to known list

### Linked issues
Partly resolve #1931

Author: pritishpai

src/databricks/labs/ucx/source_code/known.json

@@ -5428,6 +5428,17 @@
     "google_auth_oauthlib.interactive": [],
     "google_auth_oauthlib.tool": []
   },
+  "google-cloud-core": {
+    "google.cloud._helpers": [],
+    "google.cloud._http": [],
+    "google.cloud._testing": [],
+    "google.cloud.client": [],
+    "google.cloud.environment_vars": [],
+    "google.cloud.exceptions": [],
+    "google.cloud.obsolete": [],
+    "google.cloud.operation": [],
+    "google.cloud.version": []
+  },
   "google-pasta": {
     "pasta": []
   },
@@ -30796,4 +30807,4 @@
     "zipp.compat.py310": [],
     "zipp.glob": []
   }
-}
+}