Bump japicmp-maven-plugin from 0.15.3 to 0.15.4 (#1651)

Bumps [japicmp-maven-plugin](https://github.com/siom79/japicmp) from 0.15.3 to 0.15.4.
- [Release notes](https://github.com/siom79/japicmp/releases)
- [Changelog](https://github.com/siom79/japicmp/blob/master/release.py)
- [Commits](siom79/japicmp@japicmp-base-0.15.3...japicmp-base-0.15.4)

---
updated-dependencies:
- dependency-name: com.github.siom79.japicmp:japicmp-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -192,7 +192,7 @@
         <!-- API version compat check - https://siom79.github.io/japicmp/ -->
         <groupId>com.github.siom79.japicmp</groupId>
         <artifactId>japicmp-maven-plugin</artifactId>
-        <version>0.15.3</version>
+        <version>0.15.4</version>
         <configuration>
           <!-- hard code previous version; can't detect when running stateless on build server -->
           <oldVersion>