Restored step to also install dotnet 8.0 in the Linux builds.

Author: dlemstra

.github/workflows/main.yml

@@ -26,6 +26,10 @@ jobs:
     - name: Install dependencies
       run: build/linux-x64/install.dependencies.sh
 
+    - uses: actions/setup-dotnet@v5
+      with:
+        dotnet-version: 8.x
+
     - name: Install Magick.Native
       run: build/shared/install.Magick.Native.sh "dlemstra" "${{ secrets.GITHUB_TOKEN }}" linux x64
 
@@ -55,6 +59,10 @@ jobs:
     - name: Install dependencies
       run: build/linux-musl-x64/install.dependencies.sh
 
+    - uses: actions/setup-dotnet@v5
+      with:
+        dotnet-version: 8.x
+
     - name: Install Magick.Native
       run: build/shared/install.Magick.Native.sh "dlemstra" "${{ secrets.GITHUB_TOKEN }}" linux-musl x64