Add @pcuenca to code owners for tasks (#711)

@pcuenca is quite active on `@huggingface/tasks` PRs so it's an easy way
to get notified on relevant PRs

Author: coyotte508

CODEOWNERS

@@ -4,7 +4,7 @@
 
 # Ownership for the Tasks Package
 
-/packages/tasks/ @osanseviero @SBrandeis @gary149 @Wauplin @julien-c
+/packages/tasks/ @osanseviero @SBrandeis @gary149 @Wauplin @julien-c @pcuenca
 
 # Ownership for the Hub Package