Bump spring-cloud-dependencies from Hoxton.SR5 to Hoxton.SR6

Bumps [spring-cloud-dependencies](https://github.com/spring-cloud/spring-cloud-build) from Hoxton.SR5 to Hoxton.SR6.
- [Release notes](https://github.com/spring-cloud/spring-cloud-build/releases)
- [Commits](https://github.com/spring-cloud/spring-cloud-build/commits)

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

pom.xml

@@ -36,7 +36,7 @@
         <nexus-staging-maven-plugin.version>1.6.8</nexus-staging-maven-plugin.version>
         <jacoco.version>0.8.5</jacoco.version>
         <coveralls-maven-plugin.version>4.3.0</coveralls-maven-plugin.version>
-        <spring-cloud.version>Hoxton.SR5</spring-cloud.version>
+        <spring-cloud.version>Hoxton.SR6</spring-cloud.version>
         <awaitility.version>4.0.2</awaitility.version>
 
         <jacoco.it.execution.data.file>${project.build.directory}/coverage-reports/jacoco.exec</jacoco.it.execution.data.file>