Make Dependabot add skip-changelog label

So we don't have to add it manually.

Author: m1kola

.github/dependabot.yml

@@ -16,6 +16,10 @@ updates:
       - dependency-name: k8s.io/client-go
       - dependency-name: k8s.io/code-generator
       - dependency-name: sigs.k8s.io/controller-runtime
+    labels:
+      - dependencies
+      - go
+      - skip-changelog
 
   - package-ecosystem: pip
     directory: "/"
@@ -29,3 +33,7 @@ updates:
           - "*"
     ignore:
        - dependency-name: kubernetes
+    labels:
+      - dependencies
+      - python
+      - skip-changelog