Use cache@v4 and checkout@v4

.github/workflows/unit-tests.yml

@@ -18,21 +18,21 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Build River
         uses: ./.github/actions/install-env
         with:
           python-version: "3.12"
 
       - name: Cache River datasets
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/river_data
           key: ${{ runner.os }}
 
       - name: Cache scikit-learn datasets
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/scikit_learn_data
           key: ${{ runner.os }}