ci: use native ubuntu-24.04-arm runner for ARM64 Linux build

cross-compilation via 'cross' fails metadata resolution because
../airframe is an optional path dep that doesn't exist on the Ubuntu
runner. cross runs cargo metadata before entering the Docker container,
which resolves all path deps including optional ones.

Native ARM64 runner eliminates cross entirely — no Docker, no metadata
issue. Airframe is still excluded from this binary (features: huggingface)
since wgpu requires a native GPU build.

Author: Michael-A-Kuykendall

.github/workflows/release.yml

@@ -191,13 +191,12 @@ jobs:
           # Linux x86_64 - SKIPPED - Built in reuse-gate-binary job above
           # Prevents artifact naming conflict (409 error)
 
-          - os: ubuntu-latest
+          - os: ubuntu-24.04-arm
             target: aarch64-unknown-linux-gnu
             binary-name: shimmy
             artifact-name: shimmy-linux-aarch64
-            features: huggingface  # cross-compilation; Airframe requires native wgpu build
-            use-cross: true
-            optional: true
+            features: huggingface  # native ARM64 runner; Airframe requires native wgpu build
+            use-cross: false
 
           # Windows x64 — Airframe GPU engine included
           - os: windows-latest