chore: regenerate README (#562)

This PR was generated using Autosynth. 🌈


<details><summary>Log from Synthtool</summary>

```
2021-05-31 21:34:21,776 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-dataproc/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-05-31 21:34:23,051 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

```
</details>

Full log will be available here:
https://source.cloud.google.com/results/invocations/18b347ed-6674-40a9-b6d9-61de384fa827/targets

- [ ] To automatically regenerate this PR, check this box. (May take up to 24 hours.)

Author: yoshi-automation

.github/readme/synth.metadata/synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-dataproc.git",
-        "sha": "22ec4f9db66cea758126b870078ffee562aadd15"
+        "sha": "f44e361dda1c9620dce8c4b554fa7305d3a3b72d"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "a2de127f90799cd5bace653b1dcc5dd2ca8b19c9"
+        "sha": "c3e41da0fa256ad7f6b4bc76b9d069dedecdfef4"
       }
     }
   ]

README.md

@@ -39,7 +39,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-dataproc</artifactId>
-  <version>1.4.2</version>
+  <version>1.4.3</version>
 </dependency>
 
 ```