Sets up .NET for generator workflow

Adds a step to install the .NET SDK for the generator workflow, specifying version 9.x.

Author: Keboo

.github/workflows/generate.yml

@@ -35,6 +35,10 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v5
+      - name: Set up .NET
+        uses: actions/setup-dotnet@v5
+        with:
+          dotnet-version: '9.x'
       - name: Generate
         working-directory: generator
         run: dotnet run