[10.x] Fix Model::replicate() when using unique keys

[axlon]

Fixes #48629

What problem does this PR fix?

When replicating a model, some columns are purposefully omitted from the replica so that the original record will not be overwritten in the database.
By default replication excludes the model's primary key but not any additional unique keys. This means that these keys will need to be excluded manually or manually overwritten before saving. This is only a problem when using HasUuids or HasUlids on columns that are not the model's primary key.

For example, assume the following migration and model:

Schema::create('users', static function (Blueprint $table) {
    $table->id();
    $table->uuid()->unique();
    $table->timestamps();
});

class User extends Model
{
    use HasUuids;

    public function uniqueIds()
    {
        return ['uuid'];
    }
}

The following will fail in a unique constraint violation:

$user = User::firstOrFail();
$otherUser = tap($user->replicate())->save();

[driesvints]

@axlon can you please add a thorough description and not just link to an issue? thanks