MAINT: update cache and rebuild

.github/workflows/cache.yml

@@ -8,22 +8,22 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Setup Anaconda
-        uses: conda-incubator/setup-miniconda@v2
+        uses: conda-incubator/setup-miniconda@v3
         with:
           auto-update-conda: true
           auto-activate-base: true
           miniconda-version: 'latest'
-          python-version: 3.8
+          python-version: 3.12
           environment-file: environment.yml
           activate-environment: quantecon
       - name: Build HTML
         shell: bash -l {0}
         run: |
           jb build lectures --path-output ./ -W --keep-going
       - name: Upload "_build" folder (cache)
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: build-cache
           path: _build