I don't think it was ever enforced but it is in the 21/22 FA rules:-
An indirect free kick is awarded if a goalkeeper, inside their penalty area, commits any of the following offences:
- controls the ball with the hand/arm for more than six seconds before releasing
I understand why a referee would be lenient if the goalie holds the ball for 7/8 seconds, but if a team is clearly timewasting they should enforce the rule.
When teams start wasting time ( even if it's early in the game as on Saturday), I think the referee should tell the captain that it has to stop and the next player who does it will be booked - as per rules of the game:-
Referees must caution players who delay the restart of play by:
- appearing to take a throw-in but suddenly leaving it to a team-mate to take
- delaying leaving the field of play when being substituted
- excessively delaying a restart
- kicking or carrying the ball away, or provoking a confrontation by deliberately touching the ball after the referee has stopped play
- taking a free kick from the wrong position to force a retake