ci: adds a dependabot vitest group to reduce spam

Author: baywet

.github/dependabot.yml

@@ -1,12 +1,16 @@
 version: 2
 updates:
-- package-ecosystem: github-actions
-  directory: "/"
-  schedule:
-    interval: daily
-  open-pull-requests-limit: 10
-- package-ecosystem: npm
-  directory: "/"
-  schedule:
-    interval: daily
-  open-pull-requests-limit: 10
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: daily
+    open-pull-requests-limit: 10
+  - package-ecosystem: npm
+    directory: "/"
+    schedule:
+      interval: daily
+    open-pull-requests-limit: 10
+    groups:
+      vitest:
+        patterns:
+          - "*vitest*"