Fix spelling typo (#25514)

CODE_OF_CONDUCT.md

@@ -12,7 +12,7 @@ Specifically:
 Should you experience anything that makes you feel unwelcome in Flutter's
 community, please contact someone on the team, for instance
 [Ian](mailto:ian@hixie.ch) or [Tim](mailto:timsneath@google.com). We will
-not tolerate harrasment from anyone in Flutter's community, even outside
+not tolerate harassment from anyone in Flutter's community, even outside
 of Flutter's public communication channels.
 
 ## Conflict resolution