Bump the production-dependencies group across 1 directory with 5 updates

Bumps the production-dependencies group with 5 updates in the /backend directory:

| Package | From | To |
| --- | --- | --- |
| [cron](https://github.com/kelektiv/node-cron) | `3.2.1` | `3.3.1` |
| [dotenv](https://github.com/motdotla/dotenv) | `16.4.5` | `16.4.7` |
| [eventsource](https://github.com/EventSource/eventsource) | `2.0.2` | `3.0.2` |
| [express-rate-limit](https://github.com/express-rate-limit/express-rate-limit) | `7.4.1` | `7.5.0` |
| [mysql2](https://github.com/sidorares/node-mysql2) | `3.11.4` | `3.11.5` |



Updates `cron` from 3.2.1 to 3.3.1
- [Release notes](https://github.com/kelektiv/node-cron/releases)
- [Changelog](https://github.com/kelektiv/node-cron/blob/main/CHANGELOG.md)
- [Commits](kelektiv/node-cron@v3.2.1...v3.3.1)

Updates `dotenv` from 16.4.5 to 16.4.7
- [Changelog](https://github.com/motdotla/dotenv/blob/master/CHANGELOG.md)
- [Commits](motdotla/dotenv@v16.4.5...v16.4.7)

Updates `eventsource` from 2.0.2 to 3.0.2
- [Release notes](https://github.com/EventSource/eventsource/releases)
- [Changelog](https://github.com/EventSource/eventsource/blob/main/CHANGELOG.md)
- [Commits](EventSource/eventsource@v2.0.2...v3.0.2)

Updates `express-rate-limit` from 7.4.1 to 7.5.0
- [Release notes](https://github.com/express-rate-limit/express-rate-limit/releases)
- [Commits](express-rate-limit/express-rate-limit@v7.4.1...v7.5.0)

Updates `mysql2` from 3.11.4 to 3.11.5
- [Release notes](https://github.com/sidorares/node-mysql2/releases)
- [Changelog](https://github.com/sidorares/node-mysql2/blob/master/Changelog.md)
- [Commits](sidorares/node-mysql2@v3.11.4...v3.11.5)

---
updated-dependencies:
- dependency-name: cron
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: production-dependencies
- dependency-name: dotenv
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: production-dependencies
- dependency-name: eventsource
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: production-dependencies
- dependency-name: express-rate-limit
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: production-dependencies
- dependency-name: mysql2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: production-dependencies
...

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

backend/package.json

@@ -16,12 +16,12 @@
   "dependencies": {
     "bunyan": "^1.8.15",
     "cors": "^2.8.5",
-    "cron": "^3.2.1",
-    "dotenv": "^16.4.5",
-    "eventsource": "^2.0.2",
+    "cron": "^3.3.1",
+    "dotenv": "^16.4.7",
+    "eventsource": "^3.0.2",
     "express": "^4.21.2",
-    "express-rate-limit": "^7.4.1",
-    "mysql2": "^3.11.4",
+    "express-rate-limit": "^7.5.0",
+    "mysql2": "^3.11.5",
     "octokit": "^4.0.2",
     "sequelize": "^6.37.5",
     "smee-client": "^2.0.4",