fix: remove hardcoded TARGETARCH from CI release workflow

The multi-platform Docker build was failing because TARGETARCH was hardcoded
to 'amd64' in the build arguments, causing FoundationDB packages to fail
installation on arm64 builds. Docker buildx automatically provides the correct
TARGETARCH for each platform during multi-platform builds.

Author: elijah-rou

.github/workflows/ci_release.yml

@@ -76,7 +76,6 @@ jobs:
           file: docker/csi.Dockerfile
           context: "{{defaultContext}}"
           build-args: |
-            TARGETARCH=amd64
             JFSCHAN=stable
             JUICEFS_CE_MOUNT_IMAGE=juicedata/mount:ce-latest
             JUICEFS_EE_MOUNT_IMAGE=juicedata/mount:ee-5.2.8-1305e8c