Remove unrequired changes to reprocess_nodes

The problem this solved has been addressed in another way, so we don't
need to do this re-analysis any more in order to fix the bug we've been
chasing.

This change is a partial revert of "Fix disappearing errors when
re-running dmypy check" from a few commits back.

Author: meshy

mypy/server/update.py

@@ -1030,10 +1030,6 @@ def key(node: FineGrainedDeferredNode) -> int:
         if graph[module_id].type_checker().check_second_pass():
             more = True
 
-    graph[module_id].detect_possibly_undefined_vars()
-    graph[module_id].generate_unused_ignore_notes()
-    graph[module_id].generate_ignore_without_code_notes()
-
     if manager.options.export_types:
         manager.all_types.update(graph[module_id].type_map())