Update Python version requirements and choices

Changed version requirement not to mention MacOS, since it is the same on all runners now, and removed 3.7 from the Action input choices

Author: aegilops

README.md

@@ -20,7 +20,7 @@ This Action and Python script lets you run one of several Python linters and typ
 
 ## Requirements
 
-- Python 3.8 or higher (3.8 or higher for MacOS on GitHub hosted runners)
+- Python 3.8 or higher
 - For Pytype, Python 3.10 or lower
 - For Fixit, Python 3.8 or higher
 - GitHub Actions

action.yml

@@ -21,7 +21,7 @@ inputs:
     description: 'The version of python to use'
     required: false
     default: '3.10'
-    choices: ['3.12', '3.11', '3.10', '3.9', '3.8', '3.7']
+    choices: ['3.12', '3.11', '3.10', '3.9', '3.8']
   ruff-version:
     description: 'The version of ruff to use'
     required: false