ensure that we test examples with a fresh env (zarr-developers#3371)

* ensure that we test examples with a fresh env

* changelog

Author: d-v-b

changes/3371.misc.rst

@@ -0,0 +1 @@
+Ensure that tests for executable examples are run in a fresh python environment.

tests/test_examples.py

@@ -72,7 +72,9 @@ def test_scripts_can_run(script_path: Path, tmp_path: Path) -> None:
     # and then test its behavior.
     # This allows the example to be useful to users who don't have Zarr installed, but also testable.
     resave_script(script_path, dest_path)
-    result = subprocess.run(["uv", "run", str(dest_path)], capture_output=True, text=True)
+    result = subprocess.run(
+        ["uv", "run", "--refresh", str(dest_path)], capture_output=True, text=True
+    )
     assert result.returncode == 0, (
         f"Script at {script_path} failed to run. Output: {result.stdout} Error: {result.stderr}"
     )