(#1324) Update python version to 3.11

[rtuck99]

Fixes #1324

Link to dodal PR (if required): #N/A
(remember to update setup.cfg with the dodal commit tag if you need it for tests to pass!)

Also fix a minor issue in deploy_hyperion.py wrt parsing of tags to versions when they aren't formatted as such

Acceptance criteria

CI runs with only python 3.11
the deploy script installs with 3.11
references to older python versions (e.g. in setup.cfg are removed)
this policy is documented in ``README`
there is an issue for moving to 3.12 when compatible ophyd-async/p4p are available

Link to GH issue for Python 3.12 is DiamondLightSource/mx-bluesky#258

[rtuck99]

Raised issue in DiamondLightSource/blueapi#432 wrt experiment plan signatures and unions