TextEditor: cleanup annotation rect cache after mark is removed

Change-Id: I8a0ab2df9d310da6025325ab3114eeadabfd4fb1
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/texteditor/textdocument.cpp

@@ -959,6 +959,7 @@ void TextDocument::removeMark(TextMark *mark)
     }
 
     removeMarkFromMarksCache(mark);
+    emit markRemoved(mark);
     mark->setBaseTextDocument(0);
     updateLayout();
 }