Skip screenshot tests by default

They can be run by setting an enviroment variable.
Run the screenshot tests in CI; they will generate new screenshots,
but we only care (in CI) about checking that they don't fail.

.github/workflows/main.yml

@@ -38,7 +38,7 @@ jobs:
 
       - name: Run tests
         run: |
-          just test-all
+          RUN_SCREENSHOT_TESTS=True just test-all
 
       # not actually needed for tests, but we want to make sure the dev tooling
       # is still working

dotenv-sample

@@ -33,3 +33,6 @@ OTEL_EXPORTER_CONSOLE=False
 
 # To send to honecomb in dev, create a token for the development and set it here.
 # OTEL_EXPORTER_OTLP_HEADERS="x-honeycomb-team=TOKEN34"
+
+# Uncomment to run the tests that take docs screenshots
+# RUN_SCREENSHOT_TESTS=True

tests/functional/test_docs_screenshots.py

@@ -1,5 +1,7 @@
+import os
 import re
 
+import pytest
 from django.conf import settings
 from playwright.sync_api import expect
 
@@ -19,6 +21,10 @@
 }
 
 
+@pytest.mark.skipif(
+    os.getenv("RUN_SCREENSHOT_TESTS") is None,
+    reason="screenshot tests skipped; set RUN_SCREENSHOT_TESTS env variable",
+)
 def test_screenshot_from_creation_to_release(
     page, live_server, context, release_files_stubber
 ):
@@ -266,6 +272,10 @@ def do_review_and_approve(username):
     page.screenshot(path=settings.SCREENSHOT_DIR / "files_released.png")
 
 
+@pytest.mark.skipif(
+    os.getenv("RUN_SCREENSHOT_TESTS") is None,
+    reason="screenshot tests skipped; set RUN_SCREENSHOT_TESTS env variable",
+)
 def test_screenshot_withdraw_request(page, context, live_server):
     user = factories.create_user(**USER_DATA["author"])
     release_request = factories.create_request_at_status(