Update toc.yml to include new Public Preview runtime 3.5

 new Public Preview runtime 3.5

Author: jeacla

articles/synapse-analytics/toc.yml

@@ -736,6 +736,8 @@ items:
       items:
         - name: Runtime for Apache Spark overview
           href: ./spark/apache-spark-version-support.md
+        - name: Azure Synapse Apache Spark 3.5 runtime (Public Preview)
+          href: ./spark/apache-spark-35-runtime.md          
         - name: Azure Synapse Apache Spark 3.4 runtime (GA)
           href: ./spark/apache-spark-34-runtime.md
         - name: Azure Synapse Apache Spark 3.3 runtime (unsupported)