chore(deps): bump @fullcalendar/core from 6.1.10 to 6.1.15

Bumps [@fullcalendar/core](https://github.com/fullcalendar/fullcalendar/tree/HEAD/packages/core) from 6.1.10 to 6.1.15.
- [Release notes](https://github.com/fullcalendar/fullcalendar/releases)
- [Changelog](https://github.com/fullcalendar/fullcalendar/blob/main/CHANGELOG.md)
- [Commits](https://github.com/fullcalendar/fullcalendar/commits/v6.1.15/packages/core)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -30,7 +30,7 @@
     "@fortawesome/fontawesome-svg-core": "^1.2.36",
     "@fortawesome/free-solid-svg-icons": "^5.15.4",
     "@fortawesome/vue-fontawesome": "^2.0.10",
-    "@fullcalendar/core": "^6.1.9",
+    "@fullcalendar/core": "^6.1.15",
     "@fullcalendar/daygrid": "^6.1.10",
     "@fullcalendar/vue": "^6.1.10",
     "@gfx/zopfli": "^1.0.15",