Fix incorrect code for Snowflake GCS (#7287)

This was confusing, as `io_airbyte_test_staging` looks like a literal string and is not mentioned in the explanation above. Slack support context: https://app.slack.com/client/T01AB4DDR2N/C01MFR03D5W/thread/C01MFR03D5W-1634852461.058400

docs/integrations/destinations/snowflake.md

@@ -174,7 +174,7 @@ create storage INTEGRATION gcs_airbyte_integration
   STORAGE_ALLOWED_LOCATIONS = ('gcs://YOURBUCKETNAME');
 
 create stage gcs_airbyte_stage
-  url = 'gcs://io_airbyte_test_staging'
+  url = 'gcs://YOURBUCKETNAME'
   storage_integration = gcs_airbyte_integration;
 
 GRANT USAGE ON integration gcs_airbyte_integration TO ROLE AIRBYTE_ROLE;