Bump spring.version from 5.3.23 to 6.1.5

Bumps `spring.version` from 5.3.23 to 6.1.5.

Updates `org.springframework:spring-web` from 5.3.23 to 6.1.5
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](spring-projects/spring-framework@v5.3.23...v6.1.5)

Updates `org.springframework:spring-test` from 5.3.23 to 6.1.5
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](spring-projects/spring-framework@v5.3.23...v6.1.5)

---
updated-dependencies:
- dependency-name: org.springframework:spring-web
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: org.springframework:spring-test
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

server/pom.xml

@@ -31,7 +31,7 @@
     <root.basedir>${project.parent.basedir}</root.basedir>
     <!-- This is chosen based on the Spring Boot version used in exec module.
       Note this module should have no Spring Boot dependency. -->
-    <spring.version>5.3.23</spring.version>
+    <spring.version>6.1.5</spring.version>
   </properties>
 
   <dependencies>