[Kernel] RFC #29630 finale: retire sglang.jit_kernel into sglang.kernels (#32072)

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/_pr-test-check-changes.yml

@@ -93,7 +93,7 @@ jobs:
               - "python/sglang/multimodal_gen/**/!(*.md|*.ipynb)"
               - "python/sglang/srt/model_executor/runner_backend_utils/breakable_cuda_graph/**"
               - "python/sglang/srt/observability/**"
-              - "python/sglang/jit_kernel/**"
+              - "python/sglang/kernels/ops/diffusion/**"
               - "test/registered/jit/diffusion/**"
               - "test/registered/jit/benchmark/diffusion/**"
               - "python/sglang/cli/**"
@@ -101,7 +101,6 @@ jobs:
               - ".github/workflows/pr-test.yml"
               - ".github/workflows/pr-test-jit-kernel.yml"
               - "python/pyproject.toml"
-              - "python/sglang/jit_kernel/**"
               - "test/registered/jit/**"
               # sglang.kernels is the migrated kernel namespace (RFC #29630 / #30044); the
               # base-b-kernel suites import it directly, so kernel edits must run them.