[godot] Install Dotnet 6 in each job.

.github/actions/setup-godot-deps/action.yml

@@ -24,4 +24,9 @@ runs:
       run: |
         python -c "import sys; print(sys.version)"
         python -m pip install scons==4.4.0
-        scons --version
+        scons --version
+
+    - name: Setup dotnet 6
+      uses: actions/setup-dotnet@v3
+      with:
+          dotnet-version: '6.0.x'