Bump @babel/core from 7.21.4 to 7.23.2 in /backend

Bumps [@babel/core](https://github.com/babel/babel/tree/HEAD/packages/babel-core) from 7.21.4 to 7.23.2.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/main/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/commits/@babel/core@7.23.2/packages/babel-core)

---
updated-dependencies:
- dependency-name: "@babel/core"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

backend/package.json

@@ -38,7 +38,7 @@
     "rust-build": "cd rust-gbt && npm run build-release"
   },
   "dependencies": {
-    "@babel/core": "^7.21.3",
+    "@babel/core": "^7.23.2",
     "@mempool/electrum-client": "1.1.9",
     "@types/node": "^18.15.3",
     "axios": "~1.5.0",
@@ -55,7 +55,7 @@
   },
   "devDependencies": {
     "@babel/code-frame": "^7.18.6",
-    "@babel/core": "^7.21.3",
+    "@babel/core": "^7.23.2",
     "@types/compression": "^1.7.2",
     "@types/crypto-js": "^4.1.1",
     "@types/express": "^4.17.17",