Who is awarded the sack when a player is not actually tackled?

The play which most closely matches what you're describing is that at 3:12 in the 2nd. It is possible that, at the time, no specific player was awarded the sack, and they later changed it. Here is the Play-by-play:

From the NFL Guide for Statisticians, we have the following bits about sacks.

First, as to whether a QB scrambling should be considered a sack, from page 17:

When a quarterback rolls out, or a player other than the quarterback handles the ball on an option play, and with the ball in his throwing hand looks directly at an eligible receiver running a route, before being tackled or stepping out of bounds behind or at the statistical line of scrimmage, it shall be scored as a sack and any yards lost attempting to pass. If the player tucks the ball away without looking at a receiver, or lifts his arm as if to throw on an apparent designed rushing play (i.e., receivers blocking downfield or not looking back) in order to deceive the defense, the play shall be considered a rushing play.

As such, as long as Rodgers was considering throwing at some point (and wasn't playing it, Taysom Hill style, as a direct run), it is a sack.

As to who it would be credited to, read further on - section 2 under "Sacks (Defensive)":

When the player making an apparent attempt to pass steps out of bounds at or behind the statistical line of scrimmage in order to avoid imminent contact with a defensive player, credit that defensive player with a sack. If the potential passer steps out of bounds without the pressure of such imminent contact, no sack is credited to any individual defensive player.

This isn't the identical situation, but it's clearly intended the same. As such, in the case you describe, Rodgers slides to avoid being tackled by someone - and as such, he is considered sacked by that someone (presumably T.J. Edwards). The scorer could have assigned it to both players, but apparently chose not to - that is up to their discretion. It also could potentially change at some point for a variety of reasons.

Had he simply ran out of bounds (to stop the clock, for example), it would have been a "team" sack, and would have counted for a Sack (to the team stats, on both sides) but not been credited to any one player - though in my experience they usually try to credit it to someone if they can.