fix: package.json & yarn.lock to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-PATHTOREGEXP-8482416

Author: snyk-bot

package.json

@@ -14,7 +14,7 @@
   },
   "dependencies": {
     "js-yaml": "3.14.1",
-    "probot": "9.15.1"
+    "probot": "13.4.5"
   },
   "devDependencies": {
     "@types/bunyan": "1.8.11",