Reuse preinstalled .NET 10 SDK in CI

.gitea/workflows/smoke.yml

@@ -74,34 +74,43 @@ jobs:
             echo "Non-root runner detected; smoke-only test lane enabled."
           fi
 
-      - name: Install .NET SDK
+      - name: Resolve .NET SDK
         run: |
           set -euo pipefail
+
+          if command -v dotnet >/dev/null 2>&1 && dotnet --list-sdks | grep -Eq '^10\.'; then
+            echo "Using preinstalled .NET 10 SDK from PATH."
+            echo "DOTNET_CMD=dotnet" >> "$GITHUB_ENV"
+            exit 0
+          fi
+
+          echo "Preinstalled .NET 10 SDK not found. Installing local SDK copy."
           curl -fsSL https://dot.net/v1/dotnet-install.sh -o dotnet-install.sh
           bash dotnet-install.sh --channel 10.0 --quality ga --install-dir "$HOME/.dotnet"
+          echo "DOTNET_CMD=$HOME/.dotnet/dotnet" >> "$GITHUB_ENV"
 
       - name: Show .NET info
         run: |
           set -euo pipefail
-          "$HOME/.dotnet/dotnet" --info
+          "${DOTNET_CMD}" --info
 
       - name: Restore
         run: |
           set -euo pipefail
-          "$HOME/.dotnet/dotnet" restore
+          "${DOTNET_CMD}" restore
 
       - name: Build
         run: |
           set -euo pipefail
-          "$HOME/.dotnet/dotnet" build --no-restore
+          "${DOTNET_CMD}" build --no-restore
 
       - name: Smoke tests
         run: |
           set -euo pipefail
-          LIBNFTABLES_RUN_PRIVILEGED_TESTS=0 "$HOME/.dotnet/dotnet" test LibNftables.slnx --no-build --filter "Category!=Privileged"
+          LIBNFTABLES_RUN_PRIVILEGED_TESTS=0 "${DOTNET_CMD}" test LibNftables.slnx --no-build --filter "Category!=Privileged"
 
       - name: Privileged tests
         if: env.RUN_PRIVILEGED_TESTS == '1'
         run: |
           set -euo pipefail
-          LIBNFTABLES_RUN_PRIVILEGED_TESTS=1 "$HOME/.dotnet/dotnet" test LibNftables.slnx --no-build --filter "Category=Privileged"
+          LIBNFTABLES_RUN_PRIVILEGED_TESTS=1 "${DOTNET_CMD}" test LibNftables.slnx --no-build --filter "Category=Privileged"