ci: give the release link swap on GitHub runners

The v2026.9.30 tag build's arm64 publish job was killed linking the
inbuxa binary (fat LTO, one codegen unit): cannot allocate memory on the
16 GB ubuntu-24.04-arm runner. index, ghcr, release, binaries and
announce were skipped. amd64 got through on the same size of runner.

Each publish job now adds a 16 GB swap file before the build; buildx's
container has no memory limit of its own, so the linker can use it.

.github/workflows/ci.yml

@@ -228,6 +228,17 @@ jobs:
       - run: |
           sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc /opt/hostedtoolcache/CodeQL
           echo "IMAGE=${{ vars.REGISTRY }}/${GITHUB_REPOSITORY,,}" >> "$GITHUB_ENV"
+      # The release link (fat LTO, one codegen unit) outgrows the runner's
+      # 16 GB: v2026.9.30's arm64 link was killed for memory. Swap gives it
+      # room; buildx's container has no memory limit of its own, so it
+      # reaches the host's swap.
+      - run: |
+          sudo fallocate -l 16G /swap.release
+          sudo chmod 600 /swap.release
+          sudo mkswap /swap.release >/dev/null
+          sudo swapon /swap.release
+          free -g
+          df -h /
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       - uses: docker/setup-buildx-action@594f3bf4285d9ea8dc53c9a0c9c4092420091003 # v4.4.0
       - uses: docker/login-action@dbcb813823bdd20940b903addbd779551569679f # v4.6.0