🐢 ci: Raise test-packages-api timeout to 20 min (#13326)

The `Tests: @librechat/api` job in `backend-review.yml` had
`timeout-minutes: 10`. Recent runs have started getting cancelled
right at the 10-minute mark with tests still actively passing — the
log streams `PASS …` lines through the final second before
`The operation was canceled.` fires.

Looking at recent runs in the wild:
- Warm `ubuntu-latest` runners: suite finishes in ~4–5 min.
- Cold/busy runners: 10+ min. No headroom = job killed mid-suite.

The suite has grown over the last few months (OpenTelemetry, MCP
OAuth, Bedrock, the Operational Prometheus Metrics work from #13265,
plus the agents/responses harness). 10-minute ceiling that worked
before is now a tail-latency cliff.

Bump to 20 minutes. Still well below the runner's hard 6-hour cap,
generous enough to absorb runner variance, and a stuck/genuine hang
will still get killed eventually rather than billing forever.

No code changes; one-line config bump.

.github/workflows/backend-review.yml

@@ -367,7 +367,11 @@ jobs:
     name: 'Tests: @librechat/api'
     needs: build
     runs-on: ubuntu-latest
-    timeout-minutes: 10
+    # Suite typically completes in ~5 min on a warm runner, but tail-latency
+    # cancellations have started showing up: tests are actively passing right
+    # up to the timeout, then the job is killed mid-suite. Bump headroom to
+    # absorb GitHub Actions runner variance.
+    timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4