feat: add dependabot (#1362)

## Description

As part of the [issue
#159641](flutter/flutter#159641) regarding
Mason being outdated, adding DependaBot to take care of keeping
everything up to date is the go-to solution.

## Type of Change

<!--- Put an `x` in all the boxes that apply: -->

- [x] ✨ New feature (non-breaking change which adds functionality)
- [ ] 🛠️ Bug fix (non-breaking change which fixes an issue)
- [ ] ❌ Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] 🧹 Code refactor
- [ ] ✅ Build configuration change
- [ ] 📝 Documentation
- [ ] 🗑️ Chore

Author: SofiaRey

.github/workflows/dependabot.yaml

@@ -0,0 +1,7 @@
+version: 2
+enable-beta-ecosystems: true
+updates:
+  - package-ecosystem: "pub"
+    directory: "/flutter_news_template/hooks"
+    schedule:
+      interval: "daily"