Bump org.pitest:pitest-maven from 1.19.1 to 1.21.0

Bumps [org.pitest:pitest-maven](https://github.com/hcoles/pitest) from 1.19.1 to 1.21.0.
- [Release notes](https://github.com/hcoles/pitest/releases)
- [Commits](hcoles/pitest@1.19.1...1.21.0)

---
updated-dependencies:
- dependency-name: org.pitest:pitest-maven
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pom.xml

@@ -42,7 +42,7 @@
         <maven-release-plugin.version>3.1.1</maven-release-plugin.version>
         <maven-site-plugin.version>4.0.0-M16</maven-site-plugin.version>
         <maven-surefire-plugin.version>3.5.3</maven-surefire-plugin.version>
-        <pitest-maven.version>1.20.4</pitest-maven.version>
+        <pitest-maven.version>1.21.0</pitest-maven.version>
         <spotbugs-maven-plugin.version>4.9.3.0</spotbugs-maven-plugin.version>
         <versions-maven-plugin.version>2.18.0</versions-maven-plugin.version>