ci: remove self-hosted npm cache upload

Author: apstenku123

.github/workflows/e2e-matrix.yml

@@ -52,8 +52,6 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
           node-version: "22"
-          cache: "npm"
-          cache-dependency-path: vbgui/package-lock.json
       - name: Create isolated MLX Python
         run: |
           base_python=/Volumes/external/sources/cppmega.mlx/.venv/bin/python
@@ -119,8 +117,7 @@ jobs:
     steps:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
-        with: { node-version: "22", cache: "npm",
-                cache-dependency-path: vbgui/package-lock.json }
+        with: { node-version: "22" }
       - name: Create isolated MLX Python
         run: |
           base_python=/Volumes/external/sources/cppmega.mlx/.venv/bin/python
@@ -178,8 +175,7 @@ jobs:
     steps:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
-        with: { node-version: "22", cache: "npm",
-                cache-dependency-path: vbgui/package-lock.json }
+        with: { node-version: "22" }
       - name: Create isolated MLX Python
         run: |
           base_python=/Volumes/external/sources/cppmega.mlx/.venv/bin/python

docs/self_hosted_ci.md

@@ -118,4 +118,9 @@ sharding assigned all 912 tests to shard 1 while the other shards had no tests.
 The self-hosted workflow now passes `--fully-parallel`, retaining four shards
 that contain test cells rather than files. Playwright has a 12-minute global
 cap and each job has a 20-minute cap, leaving setup and artifact-upload
-headroom while still producing logs on a test timeout.
+headroom while still producing logs on a test timeout. Corrected run
+`29306678792` also exposed a 1.9 GB `setup-node` cache-save attempt after shard
+2 had passed; it spent 101 seconds packing the cache and then failed to reserve
+the key. GitHub's npm cache hook is disabled for these persistent runners;
+npm's host-local cache remains available to `npm ci` without a remote post-job
+upload.

tests/test_workflow_runner_policy.py

@@ -144,6 +144,8 @@ def test_preset_matrix_is_really_sharded_and_bounded() -> None:
     assert "--shard=${{ matrix.shard }}/4" in preset_job
     assert "timeout-minutes: 20" in preset_job
     assert "timeout-minutes: 40" not in preset_job
+    assert 'cache: "npm"' not in workflow
+    assert "cache-dependency-path:" not in workflow
 
 
 def test_core_self_hosted_jobs_use_the_shared_receipted_lane_runner() -> None: