ci: run on the amd64 runner

.gitea/workflows/ci.yml

@@ -7,11 +7,9 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
-    # The runner may be arm64; Arch Linux only ships x86_64 images, so run them emulated.
-    container:
-      image: archlinux:latest
-      options: --platform linux/amd64
+    # Arch Linux only ships x86_64 images, so pick an amd64 runner.
+    runs-on: amd64
+    container: archlinux:latest
     steps:
       - name: Install dependencies
         run: |

.gitea/workflows/release.yml

@@ -9,11 +9,9 @@ permissions:
 
 jobs:
   release:
-    runs-on: ubuntu-latest
-    # The runner may be arm64; Arch Linux only ships x86_64 images, so run them emulated.
-    container:
-      image: archlinux:latest
-      options: --platform linux/amd64
+    # Arch Linux only ships x86_64 images, so pick an amd64 runner.
+    runs-on: amd64
+    container: archlinux:latest
     steps:
       - name: Install dependencies
         run: |