Remove support for python 3.8 (#17908)

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---------

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

docs/setup/installation.md

@@ -208,7 +208,7 @@ When following this route please make sure that the [Platform-specific prerequis
 System requirements:
 
 - POSIX-compliant system (tested on Linux & OS X)
-- Python 3.8 or later, up to Python 3.11.
+- Python 3.9 or later, up to Python 3.13.
 - At least 1GB of free RAM if you want to join large public rooms like #matrix:matrix.org
 
 If building on an uncommon architecture for which pre-built wheels are