build(deps-dev): bump eventsource from 4.1.1 to 5.1.0

Bumps [eventsource](https://github.com/EventSource/eventsource) from 4.1.1 to 5.1.0.
- [Release notes](https://github.com/EventSource/eventsource/releases)
- [Changelog](https://github.com/EventSource/eventsource/blob/main/CHANGELOG.md)
- [Commits](EventSource/eventsource@v4.1.1...v5.1.0)

---
updated-dependencies:
- dependency-name: eventsource
  dependency-version: 5.1.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package-lock.json

@@ -27,7 +27,7 @@
     "glob": "13.0.6"
   },
   "devDependencies": {
-    "eventsource": "^4.1.0",
+    "eventsource": "^5.1.0",
     "fetch-mock": "^12.6.0",
     "nock": "^14.0.17",
     "nodemon": "^3.1.14",