Use specific Node.js version (22) instead of latest LTS (#2879)

This way we can manage the upgrade cycle ourselves.

.github/workflows/test.yaml

@@ -14,7 +14,7 @@ jobs:
         uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af # v4
         with:
           cache: "yarn"
-          node-version: "lts/*"
+          node-version-file: ".node-version"
       - name: Install dependencies
         run: "yarn install"
       - name: Vitest