Add FLINT 3.3.1 to the test matrix

Author: oscarbenjamin

.github/workflows/buildwheel.yml

@@ -179,7 +179,7 @@ jobs:
       fail-fast: false
       matrix:
         # Supported Flint versions:
-        flint-tag: ['v3.0.1', 'v3.1.3-p1', 'v3.2.2']
+        flint-tag: ['v3.0.1', 'v3.1.3-p1', 'v3.2.2', 'v3.3.1']
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5