CAMEL-19296: Configure checkstyle to prevent the violation

[essobedo]

Motivation

A checkstyle issue is raised which prevents the build to pass.

[camel-xml-io-dsl] [INFO] --- maven-checkstyle-plugin:3.1.2:checkstyle (default-cli) @ camel-xml-io-dsl ---
[camel-xml-io-dsl] [INFO] Starting audit...
[ERROR] /home/runner/work/camel/camel/dsl/camel-xml-io-dsl/src/generated/resources/META-INF/services/org/apache/camel/routes-loader/camel.xml:1: Missing a header - not enough lines in file. [RegexpHeader]

Modifications:

• Aligns the checkstyle configuration with the one of Camel 4.

[essobedo]

Please note that the checkstyle issue is still there because a snapshot of camel-buildtools with this change is needed to be effective

[essobedo]

So I merge it as it is and trigger a build to get a snapshot