Node v25 has been released -- new nightly is v26

Signed-off-by: Roland Asmann <[email protected]>

Author: malice00

.github/workflows/test-nodejs-nightly.yml

@@ -28,7 +28,7 @@ jobs:
       - name: Install latest Node.js
         uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6.0.0
         with:
-          node-version: 25-nightly
+          node-version: 26-nightly
       - name: Test
         run: |
           pnpm install --config.strict-dep-builds=true