* fabric: Update Loom to 0.7-SNAPSHOT
* Update to Gradle 7
Switch to CadixDev/licenser
The plugin we were using before does not support Gradle 7, and hasn't been updated in over a year.
* Remove `jcenter()` references
* Move to new JDA repo and bump version
* Use setup-java v2 and Adopt JDK 16 in gh actions
* build: Temporarily add Incendo repo for plugin resolution
Allows building until licenser has a new release
* Import indra plugin classes instead of string applies
* remove space
Co-authored-by: broccolai <me@broccol.ai>
