Installing the latest version of iopath solved it for me, as it contains a fix to strip query parameters when downloading models:

pip install -U 'git+https://github.com/facebookresearch/iopath@e348b6797c40c9eb4c96bf75e9aaf1b248297548'

Hopefully PR https://github.com/facebookresearch/detectron2/pull/5427/files can be updated and merged to fix this permanently.