Fix CI broken by fpm 0.11.0 and setup-fpm

Author: bonachea

.github/workflows/CI.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v4
 
-    - uses: fortran-lang/setup-fpm@v6.0.1
+    - uses: fortran-lang/setup-fpm@main
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}