Bump org.codehaus.plexus:plexus from 20 to 22

Bumps [org.codehaus.plexus:plexus](https://github.com/codehaus-plexus/plexus-pom) from 20 to 22.
- [Release notes](https://github.com/codehaus-plexus/plexus-pom/releases)
- [Commits](https://github.com/codehaus-plexus/plexus-pom/commits)

---
updated-dependencies:
- dependency-name: org.codehaus.plexus:plexus
  dependency-version: '22'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

README.md

@@ -1,14 +1,16 @@
 Plexus-Xml
-============
+==========
 
 [![Build Status](https://github.com/codehaus-plexus/plexus-xml/actions/workflows/maven.yml/badge.svg)](https://github.com/codehaus-plexus/plexus-xml/actions)
 [![Maven Central](https://img.shields.io/maven-central/v/org.codehaus.plexus/plexus-xml.svg?label=Maven%20Central&versionPrefix=3.)](https://search.maven.org/artifact/org.codehaus.plexus/plexus-xml)
 
 This library consists of XML classes (`org.codehaus.plexus.util.xml`) that have been extracted from [`plexus-utils`](https://github.com/codehaus-plexus/plexus-utils/) 3:
+
 > `plexus-utils` 3 = `plexus-utils` 4 + `plexus-xml` 3.
 
 For publishing [the site](https://codehaus-plexus.github.io/plexus-xml/) do the following:
 
 ```
 mvn -Preporting verify site site:stage scm-publish:publish-scm
 ```
+

pom.xml

@@ -20,7 +20,7 @@ limitations under the License.
   <parent>
     <groupId>org.codehaus.plexus</groupId>
     <artifactId>plexus</artifactId>
-    <version>20</version>
+    <version>22</version>
   </parent>
 
   <artifactId>plexus-xml</artifactId>