Bump resolverVersion from 1.9.18 to 1.9.20

Bumps `resolverVersion` from 1.9.18 to 1.9.20.

Updates `org.apache.maven.resolver:maven-resolver-api` from 1.9.18 to 1.9.20
- [Release notes](https://github.com/apache/maven-resolver/releases)
- [Commits](apache/maven-resolver@maven-resolver-1.9.18...maven-resolver-1.9.20)

Updates `org.apache.maven.resolver:maven-resolver-util` from 1.9.18 to 1.9.20
- [Release notes](https://github.com/apache/maven-resolver/releases)
- [Commits](apache/maven-resolver@maven-resolver-1.9.18...maven-resolver-1.9.20)

---
updated-dependencies:
- dependency-name: org.apache.maven.resolver:maven-resolver-api
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.apache.maven.resolver:maven-resolver-util
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -94,7 +94,7 @@
     <pluginTestingHarnessVersion>3.3.0</pluginTestingHarnessVersion>
     <maven4Version>4.0.0-alpha-4</maven4Version>
     <maven3Version>3.9.6</maven3Version>
-    <resolverVersion>1.9.18</resolverVersion>
+    <resolverVersion>1.9.20</resolverVersion>
     <slf4jVersion>1.7.36</slf4jVersion>
     <antVersion>1.10.14</antVersion>
     <maven.site.path>plugin-tools-archives/plugin-tools-LATEST</maven.site.path>