Drop support for python 3.9

Signed-off-by: Ayan Sinha Mahapatra <asmahapatra@aboutcode.org>

Author: AyanSinhaMahapatra

README.rst

@@ -7,7 +7,7 @@ simplify and normalize license expressions (such as SPDX license expressions)
 using boolean logic.
 
 - License: Apache-2.0
-- Python: 3.9+
+- Python: 3.10+
 - Homepage: https://github.com/aboutcode-org/license-expression/
 - Install: `pip install license-expression` also available in most Linux distro.
 

setup.cfg

@@ -40,7 +40,7 @@ license_files =
     README.rst
 
 [options]
-python_requires = >=3.9
+python_requires = >=3.10
 
 package_dir =
     =src