fix: fixtures/ssr2/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-SEMVER-3247795

Author: snyk-bot

fixtures/ssr2/package.json

@@ -9,7 +9,7 @@
   "dependencies": {
     "@babel/core": "7.14.3",
     "@babel/register": "7.13.16",
-    "babel-loader": "8.1.0",
+    "babel-loader": "9.1.3",
     "babel-preset-react-app": "10.0.0",
     "compression": "^1.7.4",
     "concurrently": "^5.3.0",