Switch integration tests to OffchainLabs/arbitrum-testnode action (#629)

* switch to OffchainLabs/arbitrum-testnode action for integration tests

Replace OffchainLabs/actions/run-nitro-test-node with the new
snapshot-backed OffchainLabs/arbitrum-testnode action. Uses pre-built
Docker images instead of building from source, cutting testnode
startup from ~20min to ~30sec.

- fee-token-decimals input replaces --l3-fee-token args
- Network config exported via env var instead of docker exec

* bump testnode action to v0.1.1

* speed up withdrawal integration tests with event-based confirmation

Replace polling-based waitUntilReadyToExecute (500ms interval, 5-7 RPC
calls per poll) with a test utility that listens for NodeConfirmed /
AssertionConfirmed events and resolves immediately. Also reduce
mineUntilStop interval from 15s to 1s.

* speed up integration confirmation waits

* ci: point testnode action at testnode-workspace-migration branch

Use the migrated action (l3-node -> l3-enabled input rename) and the
nc-format fast snapshot image dl-ci-fast-2 from the arbitrum-testnode-ci
package.

* ci: use autopublished testnode v0.2.2

* ci: pin testnode action to v0.2.4 interface, keep v0.2.2 images

* chore: allowlist 4 new undici advisories (<6.27.0) in audit-ci

Adds GHSA-vxpw-j846-p89q, GHSA-p88m-4jfj-68fv, GHSA-35p6-xmwp-9g52,
GHSA-g8m3-5g58-fq7m. All are dev-only via hardhat>undici (pinned 5.x);
fixes require undici >=6.27.0 which hardhat does not yet allow.

Author: douglance

.github/workflows/build-test.yml

@@ -168,11 +168,14 @@ jobs:
           cache-key: ${{ runner.os }}-yarn-${{ hashFiles('yarn.lock') }}-monorepo
 
       - name: Set up the local node
-        uses: OffchainLabs/actions/run-nitro-test-node@main
+        uses: OffchainLabs/arbitrum-testnode@v0.2.4
         with:
-          nitro-testnode-ref: release
-          l3-node: ${{ matrix.orbit-test == '1' }}
-          args: ${{ matrix.decimals == 16 && '--l3-fee-token --l3-fee-token-decimals 16' || matrix.decimals == 20 && '--l3-fee-token --l3-fee-token-decimals 20' || matrix.decimals == 18 && '--l3-fee-token' || '' }}
+          version: v0.2.2
+          image-repository: ghcr.io/offchainlabs/arbitrum-testnode-ci
+          l3-enabled: ${{ matrix.orbit-test == '1' }}
+          fee-token-decimals: ${{ matrix.decimals }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          network-config-path: packages/sdk/localNetwork.json
 
       - name: Copy .env
         run: cp ./.env-sample ./.env
@@ -182,9 +185,6 @@ jobs:
           yarn gen:abi
           yarn build
 
-      - name: Generate network file
-        run: yarn gen:network
-
       - name: Run integration tests
         env:
           NODE_OPTIONS: --no-experimental-strip-types