MANILA — In the Philippines, tens of thousands are crowding into political rallies in Manila, and the zoo there is packed. In India, millions fanned out last weekend to celebrate a Hindu festival. And in South Korea, 15,000 fans descended on a stadium in Seoul for three nights to see the K-pop band BTS perform for the first time since October 2019. Many Asian-Pacific countries are dismantling thickets of Covid rules at bewildering speeds, even though the Omicron variant of the coronavirus is still raging in parts of the region.…