build(deps): bump org.htmlunit:htmlunit from 4.17.0 to 4.21.0 (#1504)

Bumps [org.htmlunit:htmlunit](https://github.com/HtmlUnit/htmlunit) from 4.17.0 to 4.21.0.
- [Release notes](https://github.com/HtmlUnit/htmlunit/releases)
- [Commits](HtmlUnit/htmlunit@4.17.0...4.21.0)

---
updated-dependencies:
- dependency-name: org.htmlunit:htmlunit
  dependency-version: 4.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

parent/pom.xml

@@ -217,7 +217,7 @@
             <dependency>
                 <groupId>org.htmlunit</groupId>
                 <artifactId>htmlunit</artifactId>
-                <version>4.17.0</version>
+                <version>4.21.0</version>
                 <scope>test</scope>
             </dependency>
             <dependency>