Drop 3.9, its nearly EOL anyway

Signed-off-by: Max Chesterfield <max.chesterfield@zepben.com>

Author: chestm007

pyproject.toml

@@ -16,7 +16,7 @@ build-backend = "setuptools.build_meta"
 name = "zepben.eas"
 version = "0.23.0b1"
 description = "Python SDK for interacting with the Evolve App Server"
-readme = {file = "README.md", content-type = "test/markdown"}
+readme = {file = "README.md", content-type = "text/markdown"}
 license = "MPL-2.0"
 requires-python = '>=3.10'
 authors = [