docs(gcp): use external-secrets.io/v1 in SecretStore examples (#6563)

Four inline SecretStore examples used the older external-secrets.io/v1beta1
apiVersion while the page's snippets and one inline example already use v1.
Normalize them to v1 for consistency with the current API. PushSecret examples
remain v1alpha1, the version that resource is served under.

Signed-off-by: Alexander Chernov <alexander@chernov.it>

docs/provider/google-secrets-manager.md

@@ -212,7 +212,7 @@ Once the Core Controller Pod can access the Secret Manager secret(s) through GKE
 Alternatively, with projectID auto-detection (GKE only):
 
 ```yaml
-apiVersion: external-secrets.io/v1beta1
+apiVersion: external-secrets.io/v1
 kind: SecretStore
 metadata:
   name: gcp-secret-store
@@ -235,7 +235,7 @@ In practice:
 This allows portable `SecretStore` configurations on GKE without hard-coding the project when the above conditions hold:
 
 ```yaml
-apiVersion: external-secrets.io/v1beta1
+apiVersion: external-secrets.io/v1
 kind: SecretStore
 metadata:
   name: gcp-secret-store
@@ -547,7 +547,7 @@ GCP Secret Manager Regional Secrets are available to be used with both ExternalS
 In order to achieve so, add a `location` to your SecretStore definition:
 
 ```yaml
-apiVersion: external-secrets.io/v1beta1
+apiVersion: external-secrets.io/v1
 kind: SecretStore
 metadata:
   name: gcp-secret-store
@@ -574,7 +574,7 @@ By default, when you request a secret without specifying a version, the provider
 #### Configuration Example
 
 ```yaml
-apiVersion: external-secrets.io/v1beta1
+apiVersion: external-secrets.io/v1
 kind: SecretStore
 metadata:
   name: gcp-secret-store