`apt-add-repository` example doesn't work on Debian bookworm

[perlun]

Description

When adding the PPA repository on Debian, the GPG key is not properly imported.

Steps to reproduce

 $ sudo apt-add-repository -y ppa:rael-gc/rvm
gpg: WARNING: "--secret-keyring" is an obsolete option - it has no effect
gpg: keybox '/tmp/tmps007eay5/pubring.gpg' created
gpg: /tmp/tmps007eay5/trustdb.gpg: trustdb created
gpg: key 8094BB14F4E3FBBE: public key "Launchpad PPA for Rael" imported
gpg: Total number processed: 1
gpg:               imported: 1
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
gpg: no valid OpenPGP data found.

Expected behavior

The PPA key should be added to the list of trusted keys.

Actual behavior

The key is not properly added, which results in the following error in apt-get update:

Get:4 http://ppa.launchpad.net/rael-gc/rvm/ubuntu kinetic InRelease [18.1 kB]                                                              
[...]
W: GPG error: http://ppa.launchpad.net/rael-gc/rvm/ubuntu kinetic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8094BB14F4E3FBBE
E: The repository 'http://ppa.launchpad.net/rael-gc/rvm/ubuntu kinetic InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Environment info

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux bookworm/sid
Release:    testing
Codename:   bookworm

[perlun]

Downloading the key manually and adding it to the list of trusted keys like this fixed the problem:

$ curl "https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x7be3e5681146fd4f1a40eda28094bb14f4e3fbbe" | sudo tee /etc/apt/trusted.gpg.d/rael-gc_ubuntu_rvm.asc