Use 3.1.x for C# in CI

Author: mjpt777

.github/workflows/ci.yml

@@ -71,7 +71,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        dotnet: [ '3.1.301' ]
+        dotnet: [ '3.1.x' ]
     env:
       DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
       DOTNET_CLI_TELEMETRY_OPTOUT: 1
@@ -100,7 +100,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-nuget-
       - name: Setup dotnet
-        uses: actions/setup-dotnet@v2
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: ${{ matrix.dotnet }}
       - name: Build

.github/workflows/codeql.yml

@@ -88,7 +88,7 @@ jobs:
       fail-fast: false
       matrix:
         language: [ 'csharp' ]
-        dotnet: [ '3.1.301' ]
+        dotnet: [ '3.1.x' ]
     env:
       DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
       DOTNET_CLI_TELEMETRY_OPTOUT: 1