Bump org.htmlunit:htmlunit from 4.11.1 to 4.21.0

Bumps [org.htmlunit:htmlunit](https://github.com/HtmlUnit/htmlunit) from 4.11.1 to 4.21.0.
- [Release notes](https://github.com/HtmlUnit/htmlunit/releases)
- [Commits](https://github.com/HtmlUnit/htmlunit/compare/4.11.1...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] <support@github.com>

gradle/libs.versions.toml

@@ -48,7 +48,7 @@ jakarta-websocket-jakarta-websocket-client-api = { module = "jakarta.websocket:j
 jakarta-xml-bind-jakarta-xml-bind-api = "jakarta.xml.bind:jakarta.xml.bind-api:4.0.4"
 ldapsdk = "ldapsdk:ldapsdk:4.1"
 net-sourceforge-htmlunit = "net.sourceforge.htmlunit:htmlunit:2.70.0"
-org-htmlunit-htmlunit = "org.htmlunit:htmlunit:4.11.1"
+org-htmlunit-htmlunit = "org.htmlunit:htmlunit:4.21.0"
 org-apache-httpcomponents-httpclient = "org.apache.httpcomponents.client5:httpclient5:5.6"
 org-apache-kerby-simplekdc='org.apache.kerby:kerb-simplekdc:2.1.1'
 org-apache-maven-maven-resolver-provider = "org.apache.maven:maven-resolver-provider:3.9.12"