[Liger-Kernels] Fix Liger-Kernels tests hanging

[Egor-Krivov]

Resolves #5292

There's also refactoring of Liger-Kernels installation to be consistent with sglang, vllm

PR depends on:

• [CI][sglang] Fixed sglang testing, added pin, updated patch #5376

Before merging:

• Merge [CI][sglang] Fixed sglang testing, added pin, updated patch #5376
• Test third-party testing CI, there should be no hanging for liger kernels
• Test third-party benchmarks CI

[Egor-Krivov]

Test https://github.com/intel/intel-xpu-backend-for-triton/actions/runs/18781662840

[Egor-Krivov]

Since my patch got merged upstream now this PR only does refactoring
https://github.com/linkedin/Liger-Kernel/pull/917/files

[Egor-Krivov]

Liger hangs with -n 4 for some reason, but passes without parallelization after merging cache cleanup

[Egor-Krivov]

So I make tests sequential

[Egor-Krivov]

In my local experiment that doesn't change the total runtime, maybe due to the GPU being the bottleneck. We do have 1 GPU for these tests

[Egor-Krivov]

CI pass without hanging: https://github.com/intel/intel-xpu-backend-for-triton/actions/runs/18785052372

[Egor-Krivov]

Benchmark test run https://github.com/intel/intel-xpu-backend-for-triton/actions/runs/18804529483

[whitneywhtsang]

Since my patch got merged upstream now this PR only does refactoring https://github.com/linkedin/Liger-Kernel/pull/917/files

Should we update the PR title?

[Egor-Krivov]

Good benchmark run https://github.com/intel/intel-xpu-backend-for-triton/actions/runs/18839829028/job/53749195955

[Egor-Krivov]

Since my patch got merged upstream now this PR only does refactoring https://github.com/linkedin/Liger-Kernel/pull/917/files

Should we update the PR title?

This PR still changes number of runners (-n 4 removal), which helps with hanging. Without it hanging can still happen.