Change default SCHEMAS_REFRESH_EXCLUDED_TYPES to empty string

- Remove hardcoded 'results,python' default
- Allow operators to opt-in to exclusion via environment variable
- Code makes no assumptions about which types should be excluded

Author: snickerjp

redash/settings/__init__.py

@@ -51,9 +51,7 @@
 
 SCHEMAS_REFRESH_SCHEDULE = int(os.environ.get("REDASH_SCHEMAS_REFRESH_SCHEDULE", 30))
 SCHEMAS_REFRESH_TIMEOUT = int(os.environ.get("REDASH_SCHEMAS_REFRESH_TIMEOUT", 300))
-SCHEMAS_REFRESH_EXCLUDED_TYPES = set_from_string(
-    os.environ.get("REDASH_SCHEMAS_REFRESH_EXCLUDED_TYPES", "results,python")
-)
+SCHEMAS_REFRESH_EXCLUDED_TYPES = set_from_string(os.environ.get("REDASH_SCHEMAS_REFRESH_EXCLUDED_TYPES", ""))
 
 AUTH_TYPE = os.environ.get("REDASH_AUTH_TYPE", "api_key")
 INVITATION_TOKEN_MAX_AGE = int(os.environ.get("REDASH_INVITATION_TOKEN_MAX_AGE", 60 * 60 * 24 * 7))