This pull request adds an option to automatically verify SSH keys from
LDAP authentication sources.
This allows a correct authentication and verification workflow for
LDAP-enabled organizations; under normal circumstances SSH keys in LDAP
are not managed by users manually.
* Signed SSH commits can look in the UI like on GitHub, just like gpg keys today in Gitea
* SSH format can be added in gitea config
* SSH Signing worked before with DEFAULT_TRUST_MODEL=committer
`TRUSTED_SSH_KEYS` can be a list of additional ssh public key contents
to trust for every user of this instance
Closes#34329
Related #31392
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Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
