Minimum supported version of python now 3.9.

Author: CnlPepper

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "raysect"
 version = "0.9.0"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 authors = [{name = "Dr Alex Meakins et al.", email = "developers@raysect.org"}]
 description = "A Ray-tracing Framework for Science and Engineering"
 readme = {file = "README.md", content-type = "text/markdown"}