Fix npm publish script to read tag from updated nx.json path with error handling

Author: Saadnajmi

.ado/jobs/npm-publish.yml

@@ -24,7 +24,11 @@ jobs:
     - template: /.ado/templates/configure-git.yml@self
 
     - script: |
-        PUBLISH_TAG=$(jq -r '.release.version.generatorOptions.currentVersionResolverMetadata.tag' nx.json)
+        PUBLISH_TAG=$(jq -r '.release.version.versionActionsOptions.currentVersionResolverMetadata.tag' nx.json)
+        if [ -z "$PUBLISH_TAG" ] || [ "$PUBLISH_TAG" = "null" ]; then
+          echo "Error: Failed to read publish tag from nx.json"
+          exit 1
+        fi
         echo "##vso[task.setvariable variable=publishTag]$PUBLISH_TAG"
         echo "Using publish tag from nx.json: $PUBLISH_TAG"
       displayName: Read publish tag from nx.json