Bump nl.jqno.equalsverifier:equalsverifier from 3.15.1 to 3.15.4

Bumps [nl.jqno.equalsverifier:equalsverifier](https://github.com/jqno/equalsverifier) from 3.15.1 to 3.15.4.
- [Release notes](https://github.com/jqno/equalsverifier/releases)
- [Changelog](https://github.com/jqno/equalsverifier/blob/main/CHANGELOG.md)
- [Commits](jqno/equalsverifier@equalsverifier-3.15.1...equalsverifier-3.15.4)

---
updated-dependencies:
- dependency-name: nl.jqno.equalsverifier:equalsverifier
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -20,7 +20,7 @@ dependencies {
     testImplementation('com.github.npathai:hamcrest-optional:2.0.0')
     testImplementation('org.hamcrest:hamcrest:2.2')
     testImplementation('org.mockito:mockito-core:5.5.0')
-    testImplementation('nl.jqno.equalsverifier:equalsverifier:3.15.1')
+    testImplementation('nl.jqno.equalsverifier:equalsverifier:3.15.4')
 }
 
 test {