CI: build linux tests once

Author: malloch

.github/workflows/ci.yml

@@ -52,9 +52,9 @@ jobs:
         mkdir test_artifact/test
         ls ./test
         for i in ./test/*.c; do
-         mv -v "${i%%.*}" ./test_artifact/test/;
+         cp "${i%%.*}" ./test_artifact/test/;
          done
-        mv -v ./test/testcpp ./test_artifact/test/
+        cp ./test/testcpp ./test_artifact/test/
         mv ./inst ./test_artifact/
     - uses: actions/upload-artifact@v7
       with: