[Pydantic v2] Update server and compute config to use pydantic v2

[bennybp]

Description

This PR is starting the process of moving to pydantic v2.

This first step is migrating the code for server and compute manager configuration to use the pydantic v2 models. These are isolated uses and don't affect any other models, and should be simple and safe.

As a benefit, errors related to compute manager configuration should be much easier to read due to the discriminated union functionality now available.

This does sneak in a few small changes to the configuration:

• Ability to migrate from (now very old) pre-v0.50 configuration is removed
• The deprecated queue_tags is now removed from the compute manager configuration. Use compute_tags instead.
• strict_queue_tags is deprecated, but still usable for now. Replace with strict_compute_tags

Status

• Code base linted
• Ready to go