Bump matrix-auth from 2.0 to 2.6.3

Bumps [matrix-auth](https://github.com/jenkinsci/matrix-auth-plugin) from 2.0 to 2.6.3.
- [Release notes](https://github.com/jenkinsci/matrix-auth-plugin/releases)
- [Changelog](https://github.com/jenkinsci/matrix-auth-plugin/blob/master/CHANGELOG.md)
- [Commits](jenkinsci/matrix-auth-plugin@matrix-auth-2.0...matrix-auth-2.6.3)

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

pom.xml

@@ -75,7 +75,7 @@
     <dependency>
       <groupId>org.jenkins-ci.plugins</groupId>
       <artifactId>matrix-auth</artifactId>
-      <version>2.0</version>
+      <version>2.6.3</version>
       <scope>test</scope>
     </dependency>
     <dependency>