Spelling fix.

Author: hjoliver

cylc/flow/cfgspec/workflow.py

@@ -1095,7 +1095,7 @@ def get_script_common_text(this: str, example: Optional[str] = None):
 
                       foo:x? => x
 
-                   In these cases succeess is presumed to be required unless
+                   In these cases success is presumed to be required unless
                    explicitly stated otherwise, either in the graph e.g:
 
                    .. code-block:: cylc-graph

tests/unit/scripts/test_completion_server.py

@@ -721,7 +721,7 @@ def _get_current_completion_script_version(_script, lang):
 async def test_prereqs_and_outputs():
     """Test the error cases for listing task prereqs/outputs.
 
-    The succeess cases are tested in an integration test (requires a running
+    The success cases are tested in an integration test (requires a running
     scheduler).
     """
     # if no tokens are provided, no prereqs or outputs are returned