Prevent versioned_static failure when INSTALLED_APPS is a tuple

Fixes #12253

wagtail/admin/staticfiles.py

@@ -33,7 +33,7 @@ if use_version_strings:
     # INSTALLED_APPS is used as a unique value to distinguish Wagtail apps
     # and avoid exposing the Wagtail version directly
     VERSION_HASH = hashlib.sha1(
-        "".join([__version__] + settings.INSTALLED_APPS).encode(),
+        "".join([__version__] + list(settings.INSTALLED_APPS)).encode(),
     ).hexdigest()[:8]
 else:
     VERSION_HASH = None