fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-SIMPLEGIT-3177391

Author: snyk-bot

package.json

@@ -52,7 +52,7 @@
     "needle": "2.9.1",
     "p-map": "4.0.0",
     "parse-link-header": "2.0.0",
-    "simple-git": "3.15.0",
+    "simple-git": "3.16.0",
     "sleep-promise": "8.0.1",
     "snyk-request-manager": "1.8.0",
     "source-map-support": "^0.5.16",