tests: cache sample files

Author: henryborchers

.github/workflows/tox_matrix.yml

@@ -44,14 +44,23 @@ jobs:
     steps:
 
       - uses: actions/checkout@v3
+      - name: Cache sample files
+        id: cache_samples
+        uses: actions/cache@v4
+        with:
+          path: "{{ github.workspace }}"
+          key: ${{ hashFiles('sample_images.tar.gz') }}
+      - name: download sample files
+        if: steps.cache_samples.outputs.cache-hit != 'true'
+        run: curl -L https://nexus.library.illinois.edu/repository/sample-data/images/sample_images.tar.gz -o "{{ github.workspace }}/sample_images.tar.gz"
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
           cache: 'pip' # caching pip dependencies
       - name: "install Python dependencies"
         run: |
           pip install uv
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         id: cache
         with:
           path: "${{ matrix.conan_user_home }}/.conan2"
@@ -86,4 +95,4 @@ jobs:
         env:
           CONAN_COMPILER_LIBCXX: ${{ matrix.compiler_libcxx }}
           CONAN_USER_HOME: ${{ matrix.conan_user_home }}
-
+          SAMPLE_IMAGES_ARCHIVE: "{{ github.workspace }}/sample_images.tar.gz"