Bump spring-boot-starter-parent from 2.3.4.RELEASE to 2.4.0

Bumps [spring-boot-starter-parent](https://github.com/spring-projects/spring-boot) from 2.3.4.RELEASE to 2.4.0.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.3.4.RELEASE...v2.4.0)

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.3.4.RELEASE</version>
+        <version>2.4.0</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
     <groupId>no.uio.ifi</groupId>