Remove github, gitlab, bitbucket, gitea fields in the commit context

[MarcoIeni]

Is there an existing issue or pull request for this?

• I have searched the existing issues and pull requests

Feature description

#822 added the remote field and deprecated these fields. We want to remove them to optimize memory usage, as requested in #822 (review)

Desired solution

These fields don't exist anymore

Alternatives considered

keep these fields for retrocompatibility

Additional context

should we release git-cliff 3 after this change?
Or we are allowed to change this part of the changelog because it's considered "experimental"?

[orhun]

should we release git-cliff 3 after this change?
Or we are allowed to change this part of the changelog because it's considered "experimental"?

Probably not, and yes, should be fine :)