deps: Update dependency io.projectreactor:reactor-core to v3.6.4 (#1885)

Author: renovate-bot

pom.xml

@@ -219,7 +219,7 @@
       <dependency>
         <groupId>io.projectreactor</groupId>
         <artifactId>reactor-core</artifactId>
-        <version>3.6.2</version>
+        <version>3.6.4</version>
       </dependency>
       <dependency>
         <groupId>io.projectreactor.netty</groupId>