Bump reactor-core from 3.5.6 to 3.5.7

Bumps [reactor-core](https://github.com/reactor/reactor-core) from 3.5.6 to 3.5.7.
- [Release notes](https://github.com/reactor/reactor-core/releases)
- [Commits](reactor/reactor-core@v3.5.6...v3.5.7)

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

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

Author: dependabot[bot]

kotlin/pom.xml

@@ -43,7 +43,7 @@
     <dependency>
       <groupId>io.projectreactor</groupId>
       <artifactId>reactor-core</artifactId>
-      <version>3.5.6</version>
+      <version>3.5.7</version>
       <scope>test</scope>
     </dependency>
   </dependencies>