chore: dependabot for composer (#2457)

## Description

Enables dependabot for composer

## What type of PR is this? (check all applicable)
- [ ] Bug Fix
- [ ] Feature
- [ ] Refactor
- [ ] Deprecation
- [ ] Breaking Change
- [ ] Documentation Update
- [x] CI

## Checklist
- [ ] I have made corresponding changes to the documentation (`docs/`)
- [ ] I have made corresponding changes to the changelog
(`CHANGELOG.md`)

Author: DjordyKoert

.github/dependabot.yml

@@ -12,3 +12,7 @@ updates:
     schedule:
       interval: "weekly"
     versioning-strategy: increase
+  - package-ecosystem: "composer"
+    directory: "/"
+    schedule:
+      interval: "weekly"