Merge pull request #29 from dafny-lang/dotnet

Update dotnet version

Author: keyboardDrummer

action.yml

@@ -17,7 +17,7 @@ runs:
 
   - uses: actions/setup-dotnet@v4
     with:
-      dotnet-version: '6.0.x'
+      dotnet-version: '8.0.x'
 
   - if: ${{ !inputs.build-from-source }}
     uses: actions/setup-node@v4