Update to k8s 1.25 for Dashboard integration tests

The latest Pipelines release v0.51 now requires k8s 1.25 or later.
Update the version used for the Dashboard integration tests so we
can test against the latest Pipelines release.

prow/config.yaml

@@ -850,7 +850,7 @@ presubmits:
         - "--" # end kubernetes_execute_bazel flags (consider following flags as text)
         - "/usr/local/bin/kind-e2e"
         - "--k8s-version"
-        - "v1.24.x"
+        - "v1.25.x"
         - "--nodes"
         - "3"
         - "--e2e-script"