Fix build

.github/workflows/build-and-test.yml

@@ -52,11 +52,6 @@ jobs:
                   git fetch --prune --unshallow
                   git submodule -q update --init --recursive
 
-            - name: Setup DotNet SDK
-              uses: actions/setup-dotnet@v1
-              with:
-                  dotnet-version: "3.1.x"
-
             - name: Build
               shell: pwsh
               run: ./ci-build.ps1 "${{matrix.options.framework}}"
@@ -95,11 +90,6 @@ jobs:
                   git fetch --prune --unshallow
                   git submodule -q update --init --recursive
 
-            - name: Setup DotNet SDK
-              uses: actions/setup-dotnet@v1
-              with:
-                  dotnet-version: "3.1.x"
-
             - name: Pack
               shell: pwsh
               run: ./ci-pack.ps1