fix: plugins/stack-overflow-backend/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-TAR-15032660

Author: snyk-io[bot]

plugins/stack-overflow-backend/package.json

@@ -32,9 +32,9 @@
     "clean": "backstage-cli package clean"
   },
   "dependencies": {
-    "@backstage/backend-common": "workspace:^",
+    "@backstage/backend-common": "0.24.1",
     "@backstage/config": "workspace:^",
-    "@backstage/plugin-search-common": "workspace:^",
+    "@backstage/plugin-search-common": "0.3.1",
     "node-fetch": "^2.6.7",
     "qs": "^6.9.4",
     "winston": "^3.2.1"