Update dependency org.webjars.npm:frappe-gantt to v0.8.0

Author: renovate[bot]

pom.xml

@@ -46,7 +46,7 @@
   <properties>
     <licensing.version>1.29</licensing.version>
     <kanban-macro.version>1.4.0</kanban-macro.version>
-    <gantt.version>0.6.1</gantt.version>
+    <gantt.version>0.8.0</gantt.version>
     <xwiki.extension.category>application</xwiki.extension.category>
     <xwikiprocommons.version>1.0.4</xwikiprocommons.version>
   </properties>