ci: fix Node ARM release build (#971)

When we turned on fat LTO builds, we made the release build job **much**
more compute and memory intensive. The ARM runners have particularly low
memory per core, which makes them susceptible to OOM errors. To avoid
issues, I have enabled memory swap on ARM and bumped the side of the
runner.

.github/workflows/npm-publish.yml

@@ -80,17 +80,25 @@ jobs:
           - arch: x86_64
             runner: ubuntu-latest
           - arch: aarch64
-            runner: buildjet-8vcpu-ubuntu-2204-arm
+            # For successful fat LTO builds, we need a large runner to avoid OOM errors.
+            runner: buildjet-16vcpu-ubuntu-2204-arm
     steps:
       - name: Checkout
         uses: actions/checkout@v4
       # Buildjet aarch64 runners have only 1.5 GB RAM per core, vs 3.5 GB per core for
-      # x86_64 runners. Cargo defaults to spawn a job per core, but needs a lot
-      # of memory per job. Thus for ARM we need to reduce the number of jobs
-      # to avoid OOM errors when building.
+      # x86_64 runners. To avoid OOM errors on ARM, we create a swap file.
       - name: Configure aarch64 build
         if: ${{ matrix.config.arch == 'aarch64' }}
-        run: echo "CARGO_BUILD_JOBS=4" >> "$GITHUB_ENV"
+        run: |
+          free -h
+          sudo fallocate -l 16G /swapfile
+          sudo chmod 600 /swapfile
+          sudo mkswap /swapfile
+          sudo swapon /swapfile
+          echo "/swapfile swap swap defaults 0 0" >> sudo /etc/fstab
+          # print info
+          swapon --show
+          free -h
       - name: Build Linux Artifacts
         run: |
           bash ci/build_linux_artifacts.sh ${{ matrix.config.arch }}