Unable to clone project because of deprecated git protocol for submodule

[MaximeLM]

Hello,

Our CI jobs started to fail today with an error when trying to clone HTMLReader. The error is reproductible with this command:

git clone --recurse-submodules https://github.com/nolanw/HTMLReader.git

Cloning into 'HTMLReader'...
remote: Enumerating objects: 3286, done.
remote: Counting objects: 100% (64/64), done.
remote: Compressing objects: 100% (41/41), done.
remote: Total 3286 (delta 24), reused 48 (delta 17), pack-reused 3222
Receiving objects: 100% (3286/3286), 3.42 MiB | 10.50 MiB/s, done.
Resolving deltas: 100% (2123/2123), done.
Submodule 'HTMLReaderTests/html5lib' (git://github.com/html5lib/html5lib-tests.git) registered for path 'HTMLReaderTests/html5lib'
Cloning into '[...]/HTMLReader/HTMLReaderTests/html5lib'...
fatal: remote error: 
  The unauthenticated git protocol on port 9418 is no longer supported.
Please see https://github.blog/2021-09-01-improving-git-protocol-security-github/ for more information.
fatal: clone of 'git://github.com/html5lib/html5lib-tests.git' into submodule path '[...]/HTMLReader/HTMLReaderTests/html5lib' failed

Github is now rejecting the git:// protocol used to fetch the submodule HTMLReaderTests/html5lib: https://github.blog/2021-09-01-improving-git-protocol-security-github/