com.google.cloud:libraries-bom:v6 appears to break lint

[lesv]

Found in #3179 (logs

@elharo I'm still investigating, but I thought I'd give this to you incase you knew of something. It appears that checkstyle is not loading for some reason in all the updated pom's.

@kurtisvg @averikitsch @stephaniewang526 @gguuss @chingor13 @shubha-rajan @kolea2 FYI

[lesv]

Argh - it works this time - I wonder what happened.