Group otel and k8s.io updates (nginx#2200)

Problem: Otel and k8s dependencies are often upgraded all at once and
depend on one another

Solution: Instruct dependabot to group all the dependencies of the same
set of libraries in a single PR

Author: miledxz

.github/dependabot.yml

@@ -10,6 +10,13 @@ updates:
       - "**/*"
     schedule:
       interval: daily
+    groups:
+      otel:
+        patterns:
+          - "go.opentelemetry.io/otel*"
+      k8s.io:
+        patterns:
+          - "k8s.io/*"
 
   - package-ecosystem: docker
     directories: