Runner lambdas v20230202-222408

infra: Remove hardcoded ephemeral flag, use config value

Windows were hardcoded to be ephemeral but we need the ability to
actually set these to be non-ephemeral

Signed-off-by: Eli Uriegas <eliuriegasfb.com>

ghstack-source-id: 4dfacd11f858b53edb9ed38cfdf9c80c43369e45
Pull Request resolved: https://github.com/pytorch/test-infra/pull/1420