Add a preset to group Python language dependency updates

Description

By default, python language versions are grouped alongside minor and patch updates. In some situations, this is undesirable and prevents updates from easily being merged.

For example, in Lab Allocator, we're restricted to python 3.11 by an dependency on ucam-faas. Long term in the solution is to update ucam-faas to support later python version, but the immediate future the immortal update all non-major dependencies MR is unmergable without manual intervention.

Add a preset to group updates to the python language version.

Acceptance criteria

• A preset exists which groups Python language updates and python updates are not included in the update all non-major dependencies MR.

Links/references