Okay, listen. I started writing a few more gametests (see #1682), and
then thought I'd do a cheeky Gradle update. However, that broke
vanilla-extract[^1], and also triggered a load of deprecation warnings,
and at that point it was too late to separate the too.
[^1]: 8975ed5a7b
This adds SPDX license headers to all source code files, following the
REUSE[1] specification. This does not include any asset files (such as
generated JSON files, or textures). While REUSE does support doing so
with ".license" files, for now we define these licences using the
.reuse/dep5 file.
[1]: https://reuse.software/
