SWPROT-8953: ci: github: Enable arm64 again and consider armhf next

For some reason armhf is not buidling despite the tricks in helper script:

    [5/1594] Running: cargo build target unify_build
    error: failed to determine package fingerprint for build script for
    unify_attribute_poll v0.1.0
    (/.../unifysdk-src/components/unify_attribute_poll)

Could be related to symlinks:
rust-lang/cargo#9881

Amazingly no problems observed on arm64 (with same rustup versions)

Origin: #14
Signed-off-by: Philippe Coval <philippe.coval@silabs.com>

Author: rzr

.github/workflows/build-rootfs.yml

@@ -13,6 +13,8 @@ jobs:
       matrix:
         arch:
           - amd64
+          - arm64
+#         - armhf # TODO enable when reliable
     steps:
       - uses: actions/checkout@v4.1.1
         with: