Redirects go through too many steps

[nottrobin]

This redirect goes through 3 steps:
https://assets.ubuntu.com/ubuntu-server-guide -> https://assets.ubuntu.com/v1//ubuntu-server-guide -> https://assets.ubuntu.com/v1/ubuntu-server-guide -> https://assets.ubuntu.com/v1/834b1137-ubuntu-server-guide-2023-01-26.pdf

This should just be one step:
https://assets.ubuntu.com/ubuntu-server-guide -> https://assets.ubuntu.com/v1/834b1137-ubuntu-server-guide-2023-01-26.pdf

[goulinkh]

Checking the redirects:

$ wget https://assets.ubuntu.com/ubuntu-server-guide 2>&1 | grep Location
(1) Location: https://assets.ubuntu.com/v1//ubuntu-server-guide [following]
(2) Location: https://assets.ubuntu.com/v1/ubuntu-server-guide [following]
(3) Location: https://assets.ubuntu.com/v1/544d9904-ubuntu-server-guide-2024-01-22.pdf [following]

At least one redirect can be avoided easily, where the (1) and (2) could be merged.
Regarding the last one (3), the method get_asset checks for the Redirects table and then redirect to the aliased asset, this also can be removed if we replace the redirection in get_asset by a recursive call to get_asset with redirection.target_url. If we do this we need to make sure we cover infinite recursion when the requested file path and redirection's file path are the same.