chore: add SDK version support table to README (#402)

* docs: add Python version support table to README

Add a table documenting which SDK versions introduced or dropped
support for different Python versions, based on CHANGELOG.md entries.

* fix: correct Python 3.14 support version to 7.4.3

* Apply suggestions from code review

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

---------

Co-authored-by: Claude <[email protected]>
Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Author: 3 people

README.md

@@ -12,6 +12,14 @@
 
 Please see the [Python integration docs](https://posthog.com/docs/integrations/python-integration) for details.
 
+## Python Version Support
+
+| SDK Version | Python Versions Supported | Notes |
+|-------------|---------------------------|-------|
+| 7.3.1+      | 3.10, 3.11, 3.12, 3.13, 3.14 | Added Python 3.14 support |
+| 7.0.0 - 7.0.1 | 3.10, 3.11, 3.12, 3.13  | Dropped Python 3.9 support |
+| 4.0.1 - 6.x | 3.9, 3.10, 3.11, 3.12, 3.13 | Python 3.9+ required |
+
 ## Development
 
 ### Testing Locally