Cleaning up EOL releases

[Eric]

Could the data move/reorganization be the cause of recent errors we're seeing on the
Firmware Selector?  Maybe a redirect between 'downloads' and 'archive' or something
like that?

Go to https://firmware-selector.openwrt.org/
Pull down the version selector and grab, say, 22.03.7 (any older version will reproduce)
See a CORS error:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at 
    https://downloads.openwrt.org/releases/22.03.7/.overview.json.
(Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Status code: 200.

The .overview.json file is there, well-formed and accessible, it's just that access is
blocked by the CORS issue...

Eric