fix: use macos-latest for both build targets

macos-13 Intel runners are no longer available. Cross-compile x86_64
on ARM runners instead, which Rust handles natively via --target.

.github/workflows/release.yml

@@ -29,14 +29,12 @@ jobs:
     name: Build (${{ matrix.target }})
     needs: release-please
     if: needs.release-please.outputs.release_created == 'true'
-    runs-on: ${{ matrix.runner }}
+    runs-on: macos-latest
     strategy:
       matrix:
-        include:
-          - target: aarch64-apple-darwin
-            runner: macos-latest
-          - target: x86_64-apple-darwin
-            runner: macos-13
+        target:
+          - aarch64-apple-darwin
+          - x86_64-apple-darwin
     steps:
       - uses: actions/checkout@v4
         with: