Add test for kube-gcp cue-manifest step

Signed-off-by: Tom Chauveau <tom.chauveau@epitech.eu>

docs/learn/tests/kube-gcp/cue-manifest/config.cue

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"alpha.dagger.io/gcp"
+	"alpha.dagger.io/gcp/gcr"
+	"alpha.dagger.io/gcp/gke"
+)
+
+// Value created for generic reference of `kubeconfig` in `todoapp.cue`
+kubeconfig: gkeConfig.kubeconfig
+
+// gcpConfig used for Google connection
+gcpConfig: gcp.#Config
+
+// gkeConfig used for deployment
+gkeConfig: gke.#KubeConfig & {
+	// config field references `gkeConfig` value to set in once
+	config: gcpConfig
+}
+
+// gcrCreds used for remote image push
+gcrCreds: gcr.#Credentials & {
+	// config field references `gcpConfig` value to set in once
+	config: gcpConfig
+}