Fix gofmt trailing newline and align GCP IAM expiry check with cache buffer

- Remove trailing blank line in oidc_credential.go (gofmt failure)
- Change GCP IAM minimum-remaining check from 1 minute to 5 minutes
  to match the 5-minute early-refresh buffer in GetOrRefreshOIDCToken,
  preventing unnecessary STS/IAM calls for short-lived tokens

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: kbukum1

internal/oidc/actions_oidc.go

@@ -797,7 +797,7 @@ func GetGCPAccessToken(ctx context.Context, params GCPOIDCParameters, githubToke
 	}
 
 	remaining := time.Until(expireTime)
-	if remaining < 1*time.Minute {
+	if remaining < 5*time.Minute {
 		return nil, fmt.Errorf("GCP IAM token expires too soon (%v remaining, service-account: %s)", remaining, params.ServiceAccount)
 	}
 

internal/oidc/oidc_credential.go

@@ -224,4 +224,3 @@ func GetOrRefreshOIDCToken(cred *OIDCCredential, ctx context.Context) (string, e
 
 	return oidcAccessToken.Token, nil
 }
-