Bump io.projectreactor:reactor-core in the maven-dependencies group

Bumps the maven-dependencies group with 1 update: [io.projectreactor:reactor-core](https://github.com/reactor/reactor-core).


Updates `io.projectreactor:reactor-core` from 3.6.5 to 3.6.6
- [Release notes](https://github.com/reactor/reactor-core/releases)
- [Commits](reactor/reactor-core@v3.6.5...v3.6.6)

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

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

kotlin/pom.xml

@@ -42,7 +42,7 @@
     <dependency>
       <groupId>io.projectreactor</groupId>
       <artifactId>reactor-core</artifactId>
-      <version>3.6.5</version>
+      <version>3.6.6</version>
       <scope>test</scope>
     </dependency>
   </dependencies>