Switch back to abandoned evidence threshold default

0 means guaranteed findings on all reports, since they haven't been re-generated yet until after the check is done.
it was in place to test that the check worked without waiting 30 days the first time

auditree/auditree.template.json

@@ -7,7 +7,6 @@
   "org": {
     "auditree": {
       "abandoned_evidence": {
-        "threshold": 0,
         "ignore_history": true
       },
       "repo_integrity": {