Update CI scripts

Author: henrikfroehling

.github/constants.env

@@ -1,2 +1,3 @@
-DOTNET_VERSION_STABLE: '9.0.x'
+DOTNET_VERSION_CURRENT_STABLE: '9.0.x'
+DOTNET_8_VERSION_STABLE: '8.0.x'
 DOTNET_VERSION_PREVIEW: ''

.github/workflows/build.yml

@@ -75,7 +75,8 @@ jobs:
         uses: actions/setup-dotnet@v4
         with:
           dotnet-version: |
-            ${{ env.DOTNET_VERSION_STABLE }}
+            ${{ env.DOTNET_VERSION_CURRENT_STABLE }}
+            ${{ env.DOTNET_8_VERSION_STABLE }}
 
       - name: Restore dependencies
         run: dotnet restore

.github/workflows/documentation.yml

@@ -43,7 +43,8 @@ jobs:
         uses: actions/setup-dotnet@v4
         with:
           dotnet-version: |
-            ${{ env.DOTNET_VERSION_STABLE }}
+            ${{ env.DOTNET_VERSION_CURRENT_STABLE }}
+            ${{ env.DOTNET_8_VERSION_STABLE }}
 
       - name: Setup DocFX
         run: dotnet tool update -g docfx

.github/workflows/sonarcloud.yml

@@ -33,7 +33,8 @@ jobs:
         uses: actions/setup-dotnet@v4
         with:
           dotnet-version: |
-            ${{ env.DOTNET_VERSION_STABLE }}
+            ${{ env.DOTNET_VERSION_CURRENT_STABLE }}
+            ${{ env.DOTNET_8_VERSION_STABLE }}
 
       - name: Install SonarCloud scanner
         if: steps.cache-sonar-scanner.outputs.cache-hit != 'true'