Update github publishing pipeline

[WouterGritter]

This PR does two things:

• The project is now built (not published) on ANY commit and PR change on any branch, ensuring any PR and branch will pass the checkstyle checks.
• Instead of publishing all jars built, which is unnecessary (as we are going to publish other artifacts like api through maven), we only publish the server jar (proxy/build/libs/velocity-proxy-3.5.0-SNAPSHOT-all.jar, or whatever version). We now upload this jar under a different name: velocity-ctd-VERSION-TAG.jar, e.g. velocity-ctd-3.5.0-SNAPSHOT-195.jar. This is in-line with how Velocity distributes their server jar here, the current version is velocity-3.5.0-SNAPSHOT-595.jar with 595 being the build nr/tag.