Update coverage.yml

Signed-off-by: Derek Gooding <djgooding@live.com>

Author: DerekGooding

.github/workflows/coverage.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: '8.0.x'
+          dotnet-version: '9.0.x'
 
       - name: Restore dependencies
         run: dotnet restore