Bug 1600555 - excludes => exclude r=marco

Differential Revision: https://phabricator.services.mozilla.com/D55658

--HG--
extra : moz-landing-system : lando

tools/lint/codespell.yml

@@ -52,7 +52,7 @@ codespell:
         - tools/docs/
         - tools/lint/
         - tools/tryselect/
-    excludes:
+    exclude:
         - tools/lint/test/test_codespell.py
     # List of extensions coming from:
     # tools/lint/{flake8,eslint}.yml