build!: remove support for Python 3.7

pyproject.toml

@@ -19,7 +19,7 @@ classifiers = [
 ]
 
 [tool.poetry.dependencies]
-python = ">=3.7,<3.11"
+python = ">=3.8,<3.11"
 skyfield = "^1.21"
 skyfield-data = ">=3,<5"
 python-dateutil = "^2.8"