make alpine dockerfile arch-agnostic

.woodpecker/update-package-index.yaml

@@ -14,7 +14,7 @@ matrix:
 steps:
   - name: Upload PACKAGES files
     secrets: [red_hat_dev_pw, aws_access_key_id, aws_secret_access_key, pgpass, git_ro_token, GITHUB_PAT]
-    image: docker.io/devxygmbh/arm-binaries-r-${PLATFORM}
+    image: docker.io/devxygmbh/arm64-binaries-r-${PLATFORM}
     pull: true
     environment:
       GIT_USER: pat-s
@@ -22,7 +22,7 @@ steps:
       R_PKG_CACHE_DIR: /mnt/cache/pkgcache
       R_LIBS_USER: /mnt/cache/R-pkgs
     volumes:
-      - arm-binaries-r-dep-cache-${PLATFORM}:/mnt/cache
+      - arm64-binaries-r-dep-cache-${PLATFORM}:/mnt/cache
     commands:
       # download latest package version (avoid having to rebuild image every time)
       # rscript_startup arg: required to pass down global option to future workers https://github.com/HenrikBengtsson/future/issues/134#issuecomment-2245666169