unembargo: move URLs from "datalad" to "web" remote

[yarikoptic]

Joey implemented a new command reregisterurl in 10.20240227-39-g016d1bee88 with this example shown

joey@darkstar:~/tmp/x>git-annex registerurl WORM--bar http://example.com/bar.foo
registerurl http://example.com/bar.foo ok

joey@darkstar:~/tmp/x> git-annex whereis --key WORM--bar
whereis WORM--bar (1 copy)
    dca0b5f9-659a-4928-84db-ff9fd74d8fc8 -- [foo]

  foo: http://example.com/bar.foo
ok

joey@darkstar:~/tmp/x>git-annex reregisterurl WORM--bar --move-from=foo
reregisterurl WORM--bar ok

joey@darkstar:~/tmp/x>git-annex whereis --key WORM--bar
whereis WORM--bar (2 copies)
    00000000-0000-0000-0000-000000000001 -- web
    dca0b5f9-659a-4928-84db-ff9fd74d8fc8 -- [foo]

  web: http://example.com/bar.foo
ok

so upon unembargo we could migrate URLs from datalad special remote to regular web and populate direct S3 URLs.