Update default python to 3.11 in gemnasium-python image

Why are we doing this work

Following the deprecation of python 3.9 in Deprecate the support for python 3.9 in Softwar... (#441201 - closed)

Relevant links

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan

DRAFT:

Starting with major version 5 we must:

• update python to 3.11 in gemnasium-python standard and -fips images
• stop building the additional -python-3.11 variants
• ⚠ release as v5, to be used in GitLab 17.x. Do not merge in master since this is not backward compatible.

Verification steps