fix(deps): Update dependency nl.jqno.equalsverifier:equalsverifier to v3.15.4 (#150)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [nl.jqno.equalsverifier:equalsverifier](https://www.jqno.nl/equalsverifier) ([source](https://togithub.com/jqno/equalsverifier)) | dependencies | patch | `3.15.2` -> `3.15.4` |

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### Release Notes

<details>
<summary>jqno/equalsverifier (nl.jqno.equalsverifier:equalsverifier)</summary>

### [`v3.15.4`](https://togithub.com/jqno/equalsverifier/blob/HEAD/CHANGELOG.md#3154---2023-11-29)

##### Added

-   A check for Scala with its `-Xcheckinit` flag switched on. This flag generates a field that should have been marked as synthetic, but isn't, so EqualsVerifier has to check for this field explicitly.

### [`v3.15.3`](https://togithub.com/jqno/equalsverifier/blob/HEAD/CHANGELOG.md#3153---2023-11-01)

##### Changed

-   Improves error message when packages are not "open" to EqualsVerifier. ([Issue 868](https://togithub.com/jqno/equalsverifier/issues/868))

</details>

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Author: cq-bot

lib/build.gradle

@@ -53,7 +53,7 @@ dependencies {
     testImplementation('org.junit.jupiter:junit-jupiter-api:5.10.0')
     testImplementation('org.mockito:mockito-core:5.4.0')
     testImplementation('org.mockito:mockito-junit-jupiter:5.4.0')
-    testImplementation('nl.jqno.equalsverifier:equalsverifier:3.15.2')
+    testImplementation('nl.jqno.equalsverifier:equalsverifier:3.15.4')
     testRuntimeOnly('org.junit.jupiter:junit-jupiter-engine:5.10.0')
 
     testImplementation 'org.assertj:assertj-core:3.24.2'