Bump io.projectreactor:reactor-core in /plugins/repository-azure

Bumps [io.projectreactor:reactor-core](https://github.com/reactor/reactor-core) from 3.5.6 to 3.5.9.
- [Release notes](https://github.com/reactor/reactor-core/releases)
- [Commits](reactor/reactor-core@v3.5.6...v3.5.9)

---
updated-dependencies:
- dependency-name: io.projectreactor:reactor-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

plugins/repository-azure/build.gradle

@@ -57,7 +57,7 @@ dependencies {
   implementation project(':modules:transport-netty4')
   api 'com.azure:azure-storage-blob:12.23.0'
   api 'org.reactivestreams:reactive-streams:1.0.4'
-  api 'io.projectreactor:reactor-core:3.5.6'
+  api 'io.projectreactor:reactor-core:3.5.9'
   api 'io.projectreactor.netty:reactor-netty:1.1.8'
   api 'io.projectreactor.netty:reactor-netty-core:1.1.8'
   api 'io.projectreactor.netty:reactor-netty-http:1.1.9'