chore(deps): bump actions/setup-dotnet from 3 to 4 in /.github/workflows (#1191)

Bumps [actions/setup-dotnet](https://github.com/actions/setup-dotnet) from 3 to 4.

Author: dependabot[bot]

.github/workflows/library_dafny_verification.yml

@@ -73,7 +73,7 @@ jobs:
       # dafny-reportgenerator requires next6
       # but only 7.0 is installed on macos-12-large
       - name: Setup .NET Core SDK '6.0.x'
-        uses: actions/setup-dotnet@v3
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: "6.0.x"
 

.github/workflows/test_vector_verification.yml

@@ -64,7 +64,7 @@ jobs:
       # dafny-reportgenerator requires next6
       # but only 7.0 is installed on macos-12-large
       - name: Setup .NET Core SDK '6.0.x'
-        uses: actions/setup-dotnet@v3
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: "6.0.x"