Bump spring-webflux from 5.3.25 to 5.3.28

Bumps [spring-webflux](https://github.com/spring-projects/spring-framework) from 5.3.25 to 5.3.28.
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](spring-projects/spring-framework@v5.3.25...v5.3.28)

---
updated-dependencies:
- dependency-name: org.springframework:spring-webflux
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

pom.xml

@@ -86,7 +86,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <jetty-version>10.0.14</jetty-version>
     <rxjava-version>3.1.6</rxjava-version>
-    <spring-version>5.3.25</spring-version>
+    <spring-version>5.3.28</spring-version>
     <slf4j-version>2.0.7</slf4j-version>
     <log4j2-version>2.20.0</log4j2-version>
     <reactivestreams-version>1.0.4</reactivestreams-version>