Fix sgl-kernel-mla-test path after test was moved to test/manual (#24914)

Co-authored-by: Alison Shao <a.shao@wustl.edu>
Co-authored-by: Alison Shao <54658187+alisonshao@users.noreply.github.com>

.github/workflows/pr-test.yml

@@ -158,7 +158,8 @@ jobs:
               - "python/pyproject.toml"
               - "python/sglang/jit_kernel/**"
             sgl_kernel:
-              - ".github/workflows/pr-test-sgl-kernel.yml"
+              # Intentionally excludes ".github/workflows/pr-test-sgl-kernel.yml" —
+              # see API-side detector below for rationale.
               - "sgl-kernel/**/!(*.md|THIRDPARTYNOTICES.txt|LICENSE)"
 
       # For /rerun-stage (workflow_dispatch with target_stage), dorny/paths-filter doesn't work
@@ -192,7 +193,15 @@ jobs:
           echo "..."
 
           # Check for sgl-kernel changes
-          if echo "$CHANGED_FILES" | grep -qE "^(sgl-kernel/|\.github/workflows/pr-test-sgl-kernel\.yml)"; then
+          # Note: edits to .github/workflows/pr-test-sgl-kernel.yml are intentionally
+          # NOT considered sgl-kernel changes. That filter line used to be included
+          # so workflow refactors got retested, but in practice it only catches the
+          # workflow's *consumers* (test job definitions), not the wheel build steps
+          # themselves — and gating sgl_kernel=true on it forces a 20-30 min wheel
+          # rebuild + the stage-a-test-1-gpu-small gate for pure CI-yaml edits that
+          # can't actually affect kernel behavior. PRs that touch wheel-build logic
+          # in scripts/ci/cuda/ or sgl-kernel/ still trigger correctly.
+          if echo "$CHANGED_FILES" | grep -qE "^sgl-kernel/"; then
             echo "sgl_kernel=true" >> $GITHUB_OUTPUT
             echo "Detected sgl-kernel changes"
           else