stdlib: added @dagger(input) and @dagger(output) attributes

Signed-off-by: Sam Alba <sam.alba@gmail.com>

stdlib/gcp/gcp.cue

@@ -7,9 +7,9 @@ import (
 // Base Google Cloud Config
 #Config: {
 	// GCP region
-	region: string
+	region: string @dagger(input)
 	// GCP projcet
-	project: string
+	project: string @dagger(input)
 	// GCP service key
-	serviceKey: dagger.#Secret
+	serviceKey: dagger.#Secret @dagger(input)
 }

stdlib/gcp/gcr/gcr.cue

@@ -13,7 +13,7 @@ import (
 	// GCR credentials
 	username: "oauth2accesstoken"
 	secret: {
-		string
+		string @dagger(output)
 
 		#up: [
 			op.#Load & {

stdlib/gcp/gke/gke.cue

@@ -11,15 +11,15 @@ import (
 	config: gcp.#Config
 
 	// GKE cluster name
-	clusterName: string
+	clusterName: string @dagger(input)
 
 	// Kubectl version
-	version: *"v1.19.9" | string
+	version: *"v1.19.9" | string @dagger(input)
 
 	// kubeconfig is the generated kube configuration file
 	kubeconfig: {
 		// FIXME There is a problem with dagger.#Secret type
-		string
+		string @dagger(output)
 
 		#up: [
 			op.#Load & {