Added Artifact action to CI/CD so we can download test images from runnders (#973)

* Added action

* debug output

* fixed typo

* final action

Author: timtreis

.github/workflows/test.yml

@@ -91,6 +91,16 @@ jobs:
               run: |
                   tox -vv
 
+            - name: List figures for potential debugging
+                  ls -alh /home/runner/work/squidpy/squidpy/tests/figures
+
+            - name: Archive figures generated during testing
+              if: always()
+              uses: actions/upload-artifact@v4
+              with:
+                  name: visual_test_results_${{ matrix.os }}-python${{ matrix.python }}
+                  path: /home/runner/work/squidpy/squidpy/tests/figures/*
+
             - name: Upload coverage to Codecov
               uses: codecov/codecov-action@v4
               with: