fix: package.json & package-lock.json to reduce vulnerabilities (#103)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-AXIOS-6144788

Co-authored-by: snyk-bot <snyk-bot@snyk.io>

package.json

@@ -24,7 +24,7 @@
   "author": "Open Government Products (FormSG)",
   "license": "MIT",
   "dependencies": {
-    "axios": "^1.6.2",
+    "axios": "^1.6.4",
     "tweetnacl": "^1.0.3",
     "tweetnacl-util": "^0.15.1"
   },