fix: Add PermissionDenied to ignorable exceptions in maybe_secret() (#1441)

Author: nj1973

data_validation/secret_manager.py

@@ -53,6 +53,10 @@ def maybe_secret(self, project_id: str, secret_id: str, version_id="latest") ->
             # Return the decoded payload.
             payload = response.payload.data.decode("UTF-8")
             return payload
-        except (exceptions.NotFound, exceptions.InvalidArgument):
-            # The secret does not exist and therefore we can assume it is just a token to be returned.
+        except (
+            exceptions.NotFound,
+            exceptions.InvalidArgument,
+            exceptions.PermissionDenied,
+        ):
+            # The secret does not exist or is inaccessible and therefore we can assume it is just a token to be returned.
             return secret_id