deps: update dependency org.easymock:easymock to v4 (#668)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [org.easymock:easymock](http://easymock.org) ([source](https://togithub.com/easymock/easymock)) | `3.6` -> `4.3` | [![age](https://badges.renovateapi.com/packages/maven/org.easymock:easymock/4.3/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/org.easymock:easymock/4.3/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/org.easymock:easymock/4.3/compatibility-slim/3.6)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/org.easymock:easymock/4.3/confidence-slim/3.6)](https://docs.renovatebot.com/merge-confidence/) |

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pom.xml

@@ -166,7 +166,7 @@
     <guava.version>31.0.1-jre</guava.version>
     <junit.version>4.13.2</junit.version>
     <truth.version>1.1.3</truth.version>
-    <easymock.version>3.6</easymock.version>
+    <easymock.version>4.3</easymock.version>
     <findbugs.version>3.0.2</findbugs.version>
     <threetenbp.version>1.5.2</threetenbp.version>
     <objenesis.version>3.2</objenesis.version>