group k8s prs (#3517)

Signed-off-by: Jordan Keister <[email protected]>

Author: grokspawn

.github/dependabot.yml

@@ -7,4 +7,11 @@ updates:
   - package-ecosystem: "gomod"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "weekly"
+    commit-message:
+      prefix: ":seedling:"
+    groups:
+      k8s-dependencies:
+        patterns:
+          - "k8s.io/*"
+          - "sigs.k8s.io/*"