fix(pnpm-install): skip swap setup on ARM64 runners (#276)

`pierotofy/set-swap-space@v1.0` runs:

    SWAP_FILE=$(swapon --show=NAME | tail -n 1)
    sudo swapoff $SWAP_FILE

On ARM64 GitHub runners (`ubuntu-22.04-arm64`, `ubuntu-22.04-N-core-arm64`,
etc.) there is no pre-allocated swap, so `swapon --show` returns empty,
`SWAP_FILE` is empty, and `swapoff` exits with `bad usage` (exit 16).
Every job using this composite action then fails before pnpm install
even runs.

x86_64 runners ship with an existing swap file, so the action works there.

Skip the swap step on ARM64; install runs fine with the runner's default
memory (apify-core's monorepo uses ~30 GB RAM ARM64 boxes). x86_64
behaviour is unchanged.

Discovered while migrating apify/apify-core to pnpm. The full CI suite
runs on ARM64 there, so every job in apify-core PRs that uses this action
fails on the swap step.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: B4nan

pnpm-install/action.yaml

@@ -10,8 +10,13 @@ inputs:
 runs:
   using: "composite"
   steps:
+    # Skip on ARM64: pierotofy/set-swap-space@v1.0 unconditionally calls
+    # `swapoff $(swapon --show=NAME | tail -n 1)`, which on ARM64 GitHub
+    # runners (no pre-allocated swap) resolves to `swapoff <empty>` and
+    # exits non-zero with "swapoff: bad usage". x86_64 runners ship with
+    # an existing swap file, so the action works there.
     - name: Set up swap space
-      if: runner.os == 'Linux'
+      if: runner.os == 'Linux' && runner.arch != 'ARM64'
       uses: pierotofy/set-swap-space@v1.0
       with:
         swap-size-gb: 10