ci: Switch arm64_debian from QEMU to native arm64 Docker image

.github/workflows/ci.yml

@@ -74,7 +74,7 @@ jobs:
           cache-from: type=gha
           cache-to: type=gha,mode=min
 
-  linux_debian:
+  x86_64-debian:
     name: "x86_64: Linux (Debian stable)"
     runs-on: ubuntu-latest
     needs: docker_cache
@@ -231,15 +231,13 @@ jobs:
         uses: ./.github/actions/print-logs
         if: ${{ !cancelled() }}
 
-  arm64_debian:
-    name: "ARM64: Linux (Debian stable, QEMU)"
-    runs-on: ubuntu-latest
+  arm64-debian:
+    name: "arm64: Linux (Debian stable)"
+    runs-on: ubuntu-24.04-arm
     needs: docker_cache
 
     env:
-      WRAPPER_CMD: 'qemu-aarch64'
       SECP256K1_TEST_ITERS: 16
-      HOST: 'aarch64-linux-gnu'
       WITH_VALGRIND: 'no'
       ECDH: 'yes'
       RECOVERY: 'yes'
@@ -248,27 +246,25 @@ jobs:
       MUSIG: 'yes'
       ELLSWIFT: 'yes'
       CTIMETESTS: 'no'
+      CC: ${{ matrix.cc }}
 
     strategy:
       fail-fast: false
       matrix:
-        configuration:
-          - env_vars: { } # gcc
-          - env_vars: # clang
-              CC: 'clang --target=aarch64-linux-gnu'
-          - env_vars: # clang-snapshot
-              CC: 'clang-snapshot --target=aarch64-linux-gnu'
+        cc:
+          - 'gcc'
+          - 'clang'
+          - 'clang-snapshot'
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
       - name: CI script
-        env: ${{ matrix.configuration.env_vars }}
         uses: ./.github/actions/run-in-docker-action
         with:
           dockerfile: ./ci/linux-debian.Dockerfile
-          tag: x64-debian-image
+          tag: arm64-debian-image
 
       - name: Print logs
         uses: ./.github/actions/print-logs