ci: update github actions

checkout@v3 and setup-node@v3 use node 16 under the hood, which was
deprecated in 2023.

.github/workflows/ci.yml

@@ -11,9 +11,9 @@ jobs:
     name: Foundry project
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install node
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
           cache: "yarn"
@@ -51,15 +51,15 @@ jobs:
         node-version: [20.x]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Install Foundry
         uses: foundry-rs/foundry-toolchain@v1
         with:
           version: nightly
 
       - name: Use Node.js
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
           cache: "yarn"