ci: stop using windows-2019 runners

[zerok]

The windows-2019 runners are deprecated as of 2025-06-01 and will be fully unsupported by 2025-06-30. There will be multiple brown-outs over the course of this month which might affect builds and releases unless we remove those runners.

See https://github.com/actions/runner-images/issues/12045 for details.

[CLAassistant]

All committers have signed the CLA.

[jharvey10]

Thanks :) This has been incorporated into #7153