Bump doxiaSitetoolsVersion from 1.10 to 1.11.1

Bumps `doxiaSitetoolsVersion` from 1.10 to 1.11.1.

Updates `doxia-decoration-model` from 1.10 to 1.11.1
- [Release notes](https://github.com/apache/maven-doxia-sitetools/releases)
- [Commits](apache/maven-doxia-sitetools@doxia-sitetools-1.10...doxia-sitetools-1.11.1)

Updates `doxia-site-renderer` from 1.10 to 1.11.1
- [Release notes](https://github.com/apache/maven-doxia-sitetools/releases)
- [Commits](apache/maven-doxia-sitetools@doxia-sitetools-1.10...doxia-sitetools-1.11.1)

---
updated-dependencies:
- dependency-name: org.apache.maven.doxia:doxia-decoration-model
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.apache.maven.doxia:doxia-site-renderer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

pom.xml

@@ -68,7 +68,7 @@ under the License.
     <javaVersion>8</javaVersion>
     <mavenVersion>3.2.5</mavenVersion>
     <doxiaVersion>1.11.1</doxiaVersion>
-    <doxiaSitetoolsVersion>1.10</doxiaSitetoolsVersion>
+    <doxiaSitetoolsVersion>1.11.1</doxiaSitetoolsVersion>
     <beanshell-groupId>org.apache-extras.beanshell</beanshell-groupId>
     <beanshell-artifactId>bsh</beanshell-artifactId>
     <beanshell-version>2.0b6</beanshell-version>