docs: remove custom stem in docs jobs

FUTURE_COPYBARA_INTEGRATE_REVIEW=#490 from googleapis:release-please--branches--main--components--vertexai 85ffaae
PiperOrigin-RevId: 771250625

Author: vertex-sdk-bot

.kokoro/presubmit/node18/docs.sh

@@ -32,7 +32,7 @@ npm install --no-save @google-cloud/cloud-rad@^0.4.0
 set +e
 
 # publish docs to devsite
-NO_UPLOAD=1 DOCS_METADATA_STEM=/vertex-ai/generative-ai/docs/reference/nodejs npx @google-cloud/cloud-rad . cloud-rad
+NO_UPLOAD=1 npx @google-cloud/cloud-rad . cloud-rad
 
 tar cvfz docs.tar.gz yaml
 

.kokoro/release/docs-devsite.sh

@@ -28,4 +28,4 @@ fi
 npm install
 npm install --no-save @google-cloud/cloud-rad@^0.4.0
 # publish docs to devsite
-DOCS_METADATA_STEM=/vertex-ai/generative-ai/docs/reference/nodejs npx @google-cloud/cloud-rad . cloud-rad
+npx @google-cloud/cloud-rad . cloud-rad