Update spring-boot.version to v2.3.4-RELEASE

Author: mpkorstanje

examples/spring-txn/pom.xml

@@ -13,7 +13,7 @@
 
     <properties>
         <project.Automatic-Module-Name>io.cucumber.examples.spring.txn</project.Automatic-Module-Name>
-        <spring-boot.version>2.3.3.RELEASE</spring-boot.version>
+        <spring-boot.version>2.3.4.RELEASE</spring-boot.version>
     </properties>
 
     <dependencyManagement>