fixup! refactor(resource-detector-gcp): migrate away from getEnv()

Author: pichlermarc

detectors/node/opentelemetry-resource-detector-gcp/src/detectors/GcpDetector.ts

@@ -90,12 +90,10 @@ class GcpDetector implements DetectorSync {
     attributes: ResourceAttributes,
     clusterName: string
   ): void {
-    const env = getEnv();
-
     attributes[SEMRESATTRS_K8S_CLUSTER_NAME] = clusterName;
-    attributes[SEMRESATTRS_K8S_NAMESPACE_NAME] = env.NAMESPACE;
-    attributes[SEMRESATTRS_K8S_POD_NAME] = env.HOSTNAME;
-    attributes[SEMRESATTRS_CONTAINER_NAME] = env.CONTAINER_NAME;
+    attributes[SEMRESATTRS_K8S_NAMESPACE_NAME] = process.env.NAMESPACE ?? '';
+    attributes[SEMRESATTRS_K8S_POD_NAME] = process.env.HOSTNAME ?? '';
+    attributes[SEMRESATTRS_CONTAINER_NAME] = process.env.CONTAINER_NAME ?? '';
   }
 
   /** Gets project id from GCP project metadata. */