[MAINT] Use Intel channel for build step of conda package workflow on Linux

[ndgrigorian]

This change makes the conda package workflow install 2025.1 packages instead of 2025.0, because the 2025.1 packages are not on conda-forge.

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[github-actions]

View rendered docs @ https://intelpython.github.io/dpctl/pulls/2083/index.html

[coveralls]

coverage: 84.978% (-0.006%) from 84.984%
when pulling 309a49d on use-intel-channel-for-build-linux-step
into a391844 on master.