fix(ci): delta-assert reporter leak test + raise shard timeout to 22min (#3231)

The signal-handler test asserted an absolute liveReporters===0 on a
module-global set, so any other test file in the shard holding a live
reporter flaked it — it red-flagged ~12 unrelated PR runs and one master
push in two days, purely as a function of shard composition. The delta
form pins the same claim (50 reporter lifecycles leak nothing).

The 15-minute shard timeout cancelled 13 fully-passing runs under
parallel PR load (PGLite WASM cold-starts stretch shards); the
test-status gate then reported the cancellations as failures.

Co-authored-by: Garry Tan <garrytan@gmail.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/test.yml

@@ -206,7 +206,11 @@ jobs:
     needs: cache-check
     if: needs.cache-check.outputs.hit != 'true'
     runs-on: ubuntu-latest
-    timeout-minutes: 15
+    # 22, not 15: under parallel PR load the PGLite WASM cold-starts stretch a
+    # shard past 15 min while every test is still passing — the timeout then
+    # cancels the job and the test-status gate reads it as a failure. 13 runs
+    # died this way on 2026-07-21/22 alone.
+    timeout-minutes: 22
     strategy:
       fail-fast: false
       matrix: