pipelines: update devtools-aarch64

share/spack/gitlab/cloud_pipelines/stacks/developer-tools-aarch64-linux-gnu/spack.yaml

@@ -2,12 +2,16 @@ spack:
   view: false
   packages:
     all:
-      require: target=aarch64
+      require:
+      - target=aarch64
+      prefer:
+      - '%gcc'
+
   concretizer:
     unify: true
     reuse: false
-  definitions:
+
-  - default_specs:
+  specs:
     # editors
   - neovim~no_luajit
   - py-pynvim
@@ -68,14 +72,6 @@ spack:
   - doxygen
   - meson
 
-  - arch:
-    - '%gcc target=aarch64'
-
-  specs:
-  - matrix:
-    - - $default_specs
-    - - $arch
-
   ci:
     pipeline-gen:
     - build-job: