Fix build env used for testing oneMath interface

[antonwolfy]

The PR updates the file with the conda environment used to create build conda env for testing oneMath interfaces:

• forced to use DPC++ and MKL from the latest release 2025.3 (no the latest compiler packages on conda-forge yet)
• forced to install TBB from Intel channel, because MKL is not compatible with the latest tbb from the conda-forge when cmake option MKL_THREADING=tbb_thread used

Alternatively there might an approach to create the env with strict channel priority, now the default one=flexible used, which can't guarantee the packages from high priority channel is installing.

• [x] Have you provided a meaningful PR description?
• [ ] Have you added a test, reproducer or referred to an issue with a reproducer?
• [x] Have you tested your changes locally for CPU and GPU devices?
• [x] Have you made sure that new changes do not introduce compiler warnings?
• [ ] Have you checked performance impact of proposed changes?
• [ ] Have you added documentation for your changes, if necessary?
• [ ] Have you added your changes to the changelog?

[github-actions[bot]]

View rendered docs @ https://intelpython.github.io/dpnp/index.html

[github-actions[bot]]

Array API standard conformance tests for dpnp=0.20.0dev0=py313h509198e_33 ran successfully. Passed: 1227 Failed: 0 Skipped: 9

[coveralls]

coverage: 81.51%. remained the same when pulling e6b6b0facb05865ac495b44b68f8a3c3cf5ecc52 on fix-gh-action-onemath into 0c4d440192816d3f002320bb6f6bb89cb2adf298 on master.