ci: enable zram when building for aarch64

God bless the OOM killer!

.github/workflows/wheels.yml

@@ -19,6 +19,16 @@ jobs:
             arch: aarch64
 
     steps:
+      - name: Enable zram
+        # prevent OOM killer from killing cargo (especially aarch64)
+        # PERCENTAGE=100 is safe: https://fedoraproject.org/wiki/Changes/Scale_ZRAM_to_full_memory_size
+        if: ${{ matrix.arch == 'aarch64' }}
+        run: |
+          sudo apt-get update -yq
+          sudo apt-get install -yq linux-modules-extra-azure zram-tools
+          echo -e 'CORES=1\nPERCENTAGE=100' | sudo tee -a /etc/default/zramswap
+          sudo systemctl restart zramswap
+          swapon
       - uses: actions/checkout@v3
       - uses: docker/setup-qemu-action@v2
         if: ${{ matrix.arch == 'aarch64' }}