Drop python 3.8 & 3.9 support

As per latest testing runtime, we stopped testing the
python 3.8 and 3.9 so dropping their support.

Change-Id: I6a9e980a45c5a9eeae89c67ee24ab34b11966572
Signed-off-by: Ghanshyam Maan <gmaan@ghanshyammann.com>

releasenotes/notes/drop-python38-39-cca191b19e091b6c.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Python 3.8 and 3.9 support have been removed. The minimum python version
+    supported is 3.10.

setup.cfg

@@ -6,7 +6,7 @@ summary = OpenStack Hacking Guideline Enforcement
 description_file =
     README.rst
 home_page = https://docs.openstack.org/hacking/latest/
-python_requires = >=3.8
+python_requires = >=3.10
 project_urls =
   Bug Tracker = https://bugs.launchpad.net/hacking
   Reviews = https://review.opendev.org/q/p:openstack/hacking+status:open
@@ -22,11 +22,10 @@ classifier =
     Operating System :: OS Independent
     Programming Language :: Python
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.8
-    Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
     Programming Language :: Python :: 3.12
+    Programming Language :: Python :: 3.13
 
 [files]
 packages =