Build linux-arm64 binaries

I initially tried cross-compiling from the amd64 runner, but of course that's not as easy as it should be:
https://discourse.ubuntu.com/t/failing-to-pull-arm64-apt-packages-in-ubuntu-docker-containers/59377
https://discourse.ubuntu.com/t/http-404-when-attempting-to-fetch-arm64-packages-on-24-04-1/53243
https://github.com/actions/runner-images/issues/12878
https://github.com/actions/runner-images/issues/10901

.github/workflows/release-linux-arm64.yml

@@ -0,0 +1,46 @@
+on:
+  release:
+    types: [published]
+name: Build Release Binary (Linux ARM64)
+jobs:
+  build:
+    name: Build Release Binary
+    runs-on: ubuntu-24.04-arm
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+      - name: Install dependencies
+        run: sudo apt install libssl-dev
+      - name: Build binary
+        run: make
+      - name: Upload release artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: git-crypt-artifacts
+          path: git-crypt
+  upload:
+    name: Upload Release Binary
+    runs-on: ubuntu-latest
+    needs: build
+    permissions:
+      contents: write
+    steps:
+      - name: Download release artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: git-crypt-artifacts
+      - name: Upload release asset
+        uses: actions/github-script@v3
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const fs = require("fs").promises;
+            const { repo: { owner, repo }, sha } = context;
+            await github.repos.uploadReleaseAsset({
+              owner, repo,
+              release_id: ${{ github.event.release.id }},
+              name: 'git-crypt-${{ github.event.release.name }}-linux-aarch64',
+              data: await fs.readFile('git-crypt'),
+            });