Fix required Python version

Author: pcisar

docs/index.txt

@@ -18,7 +18,7 @@ written by Helen Borrie and published by IBPhoenix_.
 
 .. seealso:: `firebird-lib`_ package for optional extensions to this driver.
 
-.. note:: Requires Python 3.8+
+.. note:: Requires Python 3.11+
 
 .. tip:: You can download docset for Dash_ (MacOS) or Zeal_ (Windows / Linux) documentation
    readers from releases_ at github.