renovate: match dl.k8s.io for K8s releases (#3573)

We have a version mismatch in our Kubernetes (e.g. `kubadm`) versions
and the versions the CLI expects to have right now, as the Renovate rule
didn't match the `dl.k8s.io` URLs introduced in c1714aa.
This fixes the issue by adjusting the Regex. Updates should work again
when the versions are back in sync.

renovate.json5

@@ -235,9 +235,9 @@
       "fileMatch": ["(^|\\/)versions.go$"],
       "matchStrings": [
         // Match kubernetes releases.
-        // example match:'  "https://storage.googleapis.com/kubernetes-release/release/v1.2.3/foo" // renovate:kubernetes-release'
+        // example match:'  "https://dl.k8s.io/v1.2.3/foo" // renovate:kubernetes-release'
         // (v1.2.3 -> currentValue)
-        " \"https:\\/\\/storage\\.googleapis\\.com\\/kubernetes-release\\/release\\/(?<currentValue>[^\\/\\s\"]+)\\/[^\"]+\"[^\\n]+\\/\\/ renovate:kubernetes-release",
+        " \"https:\\/\\/dl\\.k8s\\.io\\/(?<currentValue>[^\\/\\s\"]+)\\/[^\"]+\"[^\\n]+\\/\\/ renovate:kubernetes-release",
         // Match kubernetes releases.
         // example match:' " "v1.2.3" // renovate:kubernetes-release"'
         // (v1.2.3 -> currentValue)