Isolation parameter does not work in compose files with versions >2.3

[Techwolfy]

The isolation parameter was added in #3906, and was released in compose file version 2.1. However, it was never included in the version 3 schema file, so it causes errors with newer compose file versions.

The v3 schema documentation at https://docs.docker.com/compose/compose-file/#isolation indicates that it is still supported so it took me quite a while to find the problem. It seems that the line "isolation": {"type": "string"} (from compose/config/config_schema_v2.3.json#L163) was left out in the move to v3.0, and hasn't appeared again since. The parameter is still in compose/service.py and the tests were never removed so this is probably an easy fix.

The compose file I'm working with is intended to be deployed to a swarm, so unfortunately I can't just downgrade it. I've set "exec-opts": ["isolation=hyperv"] in C:\ProgramData\docker\config\daemon.json on each node to change the default as a workaround for now.

[shin-]

isolation is not an available option for swarm services, hence why it has not been ported to v3 yet. The first step to rectify that is to request that addition on the moby/moby issue tracker.

[shin-]

Added in docker/cli#426 on the engine side,
and as part of #5448 on the Compose side.