chore: regenerate README versions (#236)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/6ddd5311-0ad1-48dc-b18d-8b11b966c273/targets

- [ ] To automatically regenerate this PR, check this box.

Author: yoshi-automation

java-pubsub/README.md

@@ -17,7 +17,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>5.5.0</version>
+      <version>5.6.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>

java-pubsub/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-pubsub.git",
-        "sha": "09866b0d36e2dd1c994b4c91807d71552b65c8e1"
+        "sha": "cdb7ae7ebfe132be955e5ceb231c1714f07a0600"
       }
     },
     {