Update allowed python versions

Considering 3.11 is already supported, there is no
reason to not allow all <4.0 versions. This change
is essentially the same as writing >=3.7.2,<4.0.

pyproject.toml

@@ -19,7 +19,7 @@ packages = [{include = "novelai_api"}]
 "Bug Tracker" = "https://github.com/Aedial/novelai-api/issues"
 
 [tool.poetry.dependencies]
-python = ">=3.7.2,<3.12"
+python = "^3.7.2"
 aiohttp = {extras = ["speedups"], version = "^3.8.3"}
 argon2-cffi = "^21.3.0"
 PyNaCl = "^1.5.0"