checkstyle-header.txt is not taken into account

[snicoll]

The regex we have in src/checkstyle/checkstyle-header.txt is not evaluated. I've noticed this trying to update it and realizing that I could put garbage in it and the build would still pass.

[nosan]

At the moment, the header-apache2.txt file from spring-javaformat is being used. There are two options to handle this issue:

• Delete checkstyle-header.txt entirely and rely on the header-apache2.txt file
• Update the checkstyle.xml configuration to use checkstyle-header.txt. I've fixed this in my branch

Keep in mind that there is no difference between checkstyle-header.txt and header-apache2.txt

[snicoll]

My vote is to adapt checkstyle-header.txt and to configure it correctly. Given the new pattern for the header, we don't need to use a regexp anymore.

[snicoll]

We've decided to go with the approach in your branch, @nosan. Can you please open a PR? Thanks!

[nosan]

PR has been created, @snicoll

[snicoll]

Sweet, thanks again!

Closing in favor of PR #46604