[CI] Produce UR builds from ur-build-hw.yml

[ianayl]

• Allows ur-build-hw.yml to produce UR builds, which can then be reused across different CI workloads that require the UR.
• Amends benchmarking CI to use builds from ur-build-hw.yml
  • In the case that benchmarking CI is enabled in precommit in the future, UR builds used during benchmarking can directly use the builds provided from UR conformance testing in precommit.

Note:

• Conformance tests were not separated out of ur-build-hw.yml, just as testing is done in sycl-linux-build.yml as well.

[ianayl]

Test runs:

• PVC: https://github.com/intel/llvm/actions/runs/16997601996
• Currently no test run for BMG as the performance BMG runner is currently down.

I will not ask for this PR to be merged until I can get testing done on BMG as well: until then, I figured it was best to get reviews done early.