Bump dependency dotnet-sdk to v9

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -83,7 +83,7 @@ jobs:
         uses: actions/[email protected]
         with:
           # renovate: datasource=dotnet depName=dotnet-sdk
-          dotnet-version: 8.0.403
+          dotnet-version: 9.0.100
 
       - name: Cake build
         id: cake
@@ -126,7 +126,7 @@ jobs:
         uses: actions/[email protected]
         with:
           # renovate: datasource=dotnet depName=dotnet-sdk
-          dotnet-version: 8.0.403
+          dotnet-version: 9.0.100
 
       - name: Cake build
         id: cake
@@ -169,7 +169,7 @@ jobs:
         uses: actions/[email protected]
         with:
           # renovate: datasource=dotnet depName=dotnet-sdk
-          dotnet-version: 8.0.403
+          dotnet-version: 9.0.100
 
       - name: Cake build
         id: cake