Notify the import-team on import-related PRs (GH-3002)

Author: brettcannon

.github/CODEOWNERS

@@ -15,7 +15,7 @@
 **/*pyhash*                   @tiran
 
 # Import (including importlib)
-**/*import*                   @brettcannon
+**/*import*                   @python/import-team
 
 # SSL
 **/*ssl*                      @tiran