Use node 20

.devcontainer/devcontainer.json

@@ -4,7 +4,7 @@
     "postCreateCommand": "pip install tox && tox devenv -e interactive && npm ci && ./venv/bin/pre-commit install",
     "features": {
         "ghcr.io/devcontainers/features/node:1": {
-            "version": "21"
+            "version": "20"
         }
     },
     "customizations": {
@@ -19,4 +19,4 @@
             }
         }
     }
-}
+}

.github/workflows/nightly.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: '18'
+          node-version: '20'
 
       - name: Install Node dependencies
         run: npm ci

.github/workflows/publish.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Set up Node
         uses: actions/setup-node@v4
         with:
-          node-version: '18'
+          node-version: '20'
 
       - name: Install Node dependencies
         run: npm ci

.nvmrc

@@ -1 +1 @@
-16
+20

docs/contributing.md

@@ -65,7 +65,7 @@ flit install -s
 Frontend assets (React components, admin scripts, custom CSS) are bundled using Webpack. A Node.js environment is required to install and run the dependencies required to build these assets. We recommend [`nvm`](https://github.com/nvm-sh/nvm#install--update-script) for installing and using Node.js locally:
 
 ```shell
-nvm install 21
+nvm install 20
 npm ci
 ```