[RFC] Bump minimum Python version to 3.4

[Simon Marchi]

On 6/2/23 12:33, Tom Tromey via Gdb-patches wrote:
> While looking into the f-string issue, I noticed that the README
> documents 3.2 as the minimum Python version, while gdb.texinfo says
> 3.0.2.  Asking on irc, I found out that SuSE's "LTS" ships 3.4, and
> RHEL 7 ships 3.6.  Based on this I think it's reasonable to bump the
> minimum required version to 3.4.

This is fine with me, but for reference here's the previous attempt at
doing this:

https://inbox.sourceware.org/gdb-patches/20220107152921.2858909-3-simon.marchi@polymtl.ca/#r

Simon