Most people pack for the weather and forget the walking. Umrah is performed on foot, often in crowds, often at hours when you would rather be asleep. What you carry matters less than what you can carry comfortably.
Clothing
Two sets of ihram for men, and a spare. They are white, they are worn in heat, and they will need washing sooner than you expect. Women wear ordinary modest clothing, so pack for a warm country and a cool aeroplane.
Footwear
Sandals you can walk several kilometres in, and that you do not mind losing. Shoes are removed constantly, and a pair left at one door is rarely at that door when you return. A cloth bag to carry them in solves the problem entirely.
Documents
Your passport, your visa confirmation and your vaccination record. Photograph all three and keep the photographs somewhere you can reach without a signal.
The small things
An unscented soap and an unscented deodorant, because scent is not permitted in ihram. A refillable water bottle. A power bank, since you will use the phone for maps, for the group chat and for the time of every prayer.
What to leave
Anything you have packed for the possibility rather than the plan. Pharmacies, laundries and shops sit at the foot of nearly every hotel in both cities, and they are open when you need them.