ci: temporarily remove hifiberry from ci builds

hifiberry is an aarch64 machine. Currently, the workflows are not configured to do cross-compilation.

See https://discourse.nixos.org/t/nix-github-actions-aarch64/11034/4

Author: jakobkukla

.github/workflows/build.yml

@@ -14,7 +14,8 @@ jobs:
   build:
     strategy:
       matrix:
-        machine: [ matebook, pc, server, hifiberry ]
+        # FIXME: add hifiberry after fixing cross-compilation
+        machine: [ matebook, pc, server ]
     uses: ./.github/workflows/reusable-base.yml
     with:
       machine: ${{ matrix.machine }}

.github/workflows/update.yml

@@ -29,7 +29,8 @@ jobs:
     needs: update
     strategy:
       matrix:
-        machine: [ matebook, pc, server, hifiberry ]
+        # FIXME: add hifiberry after fixing cross-compilation
+        machine: [ matebook, pc, server ]
     uses: ./.github/workflows/reusable-base.yml
     with:
       machine: ${{ matrix.machine }}