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

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-BOOTSTRAP-7444580

Author: snyk-bot

package-lock.json

@@ -4,7 +4,7 @@
   "dependencies": {
     "@rails/ujs": "^6.0.0",
     "@rails/webpacker": "5.2.1",
-    "bootstrap": "^4.5.3",
+    "bootstrap": "^5.0.0",
     "jquery": "^3.5.1",
     "popper.js": "^1.16.1",
     "turbolinks": "^5.2.0"