CI: test experimental features

Author: dnicolodi

.github/workflows/tests.yml

@@ -99,10 +99,11 @@ jobs:
           - os: ubuntu-latest
             python: '3.12'
             pyproject_metadata: '==0.7.1'
-          # Tets with pyproject-metadata release candidate
+          # Tets experimental features
           - os: ubuntu-latest
             python: '3.12'
             pyproject_metadata: '==0.9.0rc1'
+            meson: '==1.6.0rc2'
 
     steps:
       - name: Checkout