Bug 1649168: Allow specifying arbitrary routes for `mach try scriptworker; r=rail

This will be used to notify releng, when failures happen in scriptworker-canary
runs.

Differential Revision: https://phabricator.services.mozilla.com/D82818

tools/tryselect/selectors/scriptworker.py

@@ -66,7 +66,7 @@ class ScriptworkerParser(BaseTryParser):
     ]
 
     common_groups = ["push"]
-    task_configs = ["worker-overrides"]
+    task_configs = ["worker-overrides", "routes"]
 
 
 def get_releases(branch):