feat: rebuild PR action task definitions correctly in CoT verification code

[bhearsum]

Without this we end up with differences in metadata, tags, routes, scopes, and sometimes the env, eg:

["[('change',\n"
 "  'metadata.owner',\n"
 "  ('action@noreply.mozilla.org', 'pr-action@noreply.mozilla.org')),\n"
 " ('change', 'metadata.name', ('Action: Train', 'PR action: Train')),\n"
 " ('change',\n"
 "  'metadata.description',\n"
 "  ('Initiate part or all of the training pipeline\\n'\n"
 "   '\\n'\n"
 "   'Action triggered by clientID '\n"
 "   '`mozilla-auth0/ad|Mozilla-LDAP|bhearsum/cli-KDQzKW`\\n',\n"
 "   'Initiate part or all of the training pipeline\\n'\n"
 "   'PR action triggered by clientID '\n"
 "   '`mozilla-auth0/ad|Mozilla-LDAP|bhearsum/cli-KDQzKW`\\n')),\n"
 " ('change',\n"
 "  'tags.createdForUser',\n"
 "  ('action@noreply.mozilla.org', 'pr-action@noreply.mozilla.org')),\n"
 " ('remove',\n"
 "  'routes',\n"
 '  [(2,\n'
 '    '
 "'index.translations.v2.translations.revision.436b91ba4ef7f5aaf7c619a9218c3c9ea0fa63d9.taskgraph.actions.Ilsl2Xq4SNivSjs4WQOEBg')]),\n"
 " ('change',\n"
 "  ['scopes', 0],\n"
 "  ('assume:repo:github.com/bhearsum/translations:action:train',\n"
 "   'assume:repo:github.com/mozilla/translations:pr-action:train')),\n"
 " ('change',\n"
 "  'payload.env.TRANSLATIONS_BASE_REPOSITORY',\n"
 "  ('https://github.com/bhearsum/translations',\n"
 "   'https://github.com/mozilla/translations')),\n"
 " ('change', 'payload.env.TRANSLATIONS_BASE_REF', ('push-plrwuypxlpum', "
 "'main')),\n"
 " ('change', 'extra.tasks_for', ('action', 'pr-action'))]"]

[bhearsum]

I was able to reproduce the problems I saw in production with verify_cot and verify the fix there, as well as in https://firefox-ci-tc.services.mozilla.com/tasks/groups/Ilsl2Xq4SNivSjs4WQOEBg, which ran a couple of dev beetmover tasks.