chore: More precise wording

src/components/schemas/api/lecture-series.yaml

@@ -36,7 +36,7 @@ properties:
   lecture_type:
     $ref: ../../enums/teaching-type.yaml
   module_execution_method:
-    $ref: ../../enums/module-execution-type.yaml
+    $ref: ../../enums/lecture-execution-type.yaml
   pages:
     description: List of pages, on which the module can be found in the PDF
     type: array