ci: fixup to prev commit

Author: gnikit

.github/workflows/CI.yml

@@ -21,7 +21,10 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-12]
         toolchain:
-          - {compiler: gcc, version: [10, 11, 12, 13]}
+          - {compiler: gcc, version: 10}
+          - {compiler: gcc, version: 11}
+          - {compiler: gcc, version: 12}
+          - {compiler: gcc, version: 13}
         build: [cmake]
         include:
           - os: ubuntu-latest