[MAINT] Use Ubuntu 24.04 in conda-package workflow

[ndgrigorian]

This PR proposes moving conda-package workflow to use Ubuntu 24.04

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[github-actions]

View rendered docs @ https://intelpython.github.io/dpctl/pulls/2362/index.html

[coveralls]

coverage: 74.462%. remained the same — migrate-ci-to-ubuntu-24.04 into master

[vlad-perevezentsev]

Would not it be better to use ubuntu-latest here instead of pinning ubuntu-24.04?
All other jobs here (and in the other workflows) use ubuntu-latest and it already resolves to 24.04