revert: "fix: static files served with different vary headers" (#26536)

posthog/settings/web.py

@@ -251,19 +251,6 @@
 ]
 STATICFILES_STORAGE = "whitenoise.storage.ManifestStaticFilesStorage"
 
-
-def add_vary_headers(headers, _path, _url):
-    """
-    we might serve static content on multiple domains, so we need to vary on Origin
-    as well as accept-encoding to avoid caching issues
-    see: https://github.com/evansd/whitenoise/blob/b3d250fd17da0e280d58b6dc4935c4573ebe8b55/docs/django.rst?plain=1#L392-L422
-    which says: The function should not return anything; changes should be made by modifying the headers dictionary directly.
-    """
-    headers["Vary"] = "Origin, Accept-Encoding"
-
-
-WHITENOISE_STATIC_HEADERS = add_vary_headers
-
 AUTH_USER_MODEL = "posthog.User"
 
 LOGIN_URL = "/login"