Use nextest test runner

.github/workflows/ci.yaml

@@ -71,9 +71,12 @@ jobs:
         uses: taiki-e/install-action@v2
         with:
           tool: cargo-insta
+      - name: "Install cargo nextest"
+        uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-nextest
       - uses: Swatinem/rust-cache@v2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
-      - name: "Tests (Ubuntu)"
-        if: ${{ matrix.os == 'ubuntu-latest' }}
-        run: cargo insta test --all --all-features --unreferenced reject
+      - name: "Tests"
+        run: cargo nextest run --all --all-features --status-level skip --failure-output immediate-final --no-fail-fast