CI: move Debian on top

.gitlab-ci.yml

 stages:
   - build
 
+native_Debian_clang:
+  tags: &native
+  - Debian
+  before_script: &debian_clang
+    - export CC=clang; export CXX=clang++
+    - cmake --version
+    - clang --version
+  stage: build
+  script: &native_scr
+    - pwd
+    - mkdir build
+    - cd build
+    - cmake .. -DCMAKE_CXX_COMPILER_LAUNCHER=ccache #-DWERROR=ON
+    - make -j6
+    - xvfb-run -a ctest -j6 --output-on-failure
+    - make package_source
+  artifacts:
+    paths:
+    - build/*gz
+    expire_in: 10 days
+
 mac:
   tags:
   - MacOS
@@ -70,27 +91,6 @@ windows:
     - build/winpackage/BornAgain*.exe
     expire_in: 1 week
 
-native_Debian_clang:
-  tags: &native
-  - Debian
-  before_script: &debian_clang
-    - export CC=clang; export CXX=clang++
-    - cmake --version
-    - clang --version
-  stage: build
-  script: &native_scr
-    - pwd
-    - mkdir build
-    - cd build
-    - cmake .. -DCMAKE_CXX_COMPILER_LAUNCHER=ccache #-DWERROR=ON
-    - make -j6
-    - xvfb-run -a ctest -j6 --output-on-failure
-    - make package_source
-  artifacts:
-    paths:
-    - build/*gz
-    expire_in: 10 days
-
 webdoc:
   rules:
   - if: '$CI_COMMIT_REF_NAME == $CI_DEFAULT_BRANCH'