⬆️ deps: Update dependency Cython to v3 (#7)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

poetry.lock

@@ -11,7 +11,7 @@ python = "^3.8"
 [tool.poetry.dev-dependencies]
 pytest = "^7.0"
 black = "^21.11b1"
-Cython = "^0.29.25"
+Cython = "^3.0.0"
 
 [tool.poetry.scripts]
 demo = "demo.__main__:main"