📇 Fix how we specify the licence

Seems you have to be explicit that it's text.

pyproject.toml

@@ -2,7 +2,7 @@
 name = "quizzical"
 version = "0.2.1"
 description = "A trivia quiz game for the terminal"
-license = "License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)"
+license = { text = "License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)"}
 authors = [
     { name = "Dave Pearson", email = "[email protected]" }
 ]