remove CACHE_MAX_DAYS feature (#2249)
* return a specific message (blocked dataset) when it's the case
* fix e2e test
* try to fix e2e
* fix e2e
* always raise with reason why dataset is not supported
* comment
* recreate the dataset on webhook to avoid mixed content
* fix tests to ensure webhook is from trusted user
* fix type
* no need for that fixture
* remove CACHE_MAX_DAYS feature
it simplifies the code, and it avoids periodic waste of resources to
refresh entries that are already OK. If we want to refresh old entries,
we can do it easily.
