Install libatomic for AArch64 test builds

Author: Chizkiyahu

.github/workflows/pull.yml

@@ -62,6 +62,7 @@ jobs:
       timeout: 90
       script: |
         set -ex
+        dnf -y install libatomic
         cmake -DCMAKE_BUILD_TYPE=Debug test -Bbuild/test
         cmake --build build/test -j9 --config Debug
         pushd build/test && ctest && popd