build(demo): update vaadin version to 23.0.12

Author: paodb

vcf-date-range-picker-demo/pom.xml

@@ -17,8 +17,7 @@
     </organization>
 
     <properties>
-        <vaadin.version>23.0.7</vaadin.version>
-        <flow.version>23.0.5</flow.version>
+        <vaadin.version>23.0.12</vaadin.version>
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>