Fix incorrect textPixelRatio argument

[anandthakker]

Closes #6075

textPixelRatio is used to scale tile coordinates to viewport coordinates; the value that was being passed here, EXTENT / tileSize, was the reciprocal of the ratio needed -- we were passing 16 instead of 0.0625.

As a result, the corners of the viewport-projected collision box that we reconstructed here,

mapbox-gl-js/src/symbol/collision_index.js

Lines 322 to 325 in f13c86e

	const x1 = blocking.x1 * tileToViewport + projectedPoint.point.x;
	const y1 = blocking.y1 * tileToViewport + projectedPoint.point.y;
	const x2 = blocking.x2 * tileToViewport + projectedPoint.point.x;
	const y2 = blocking.y2 * tileToViewport + projectedPoint.point.y;

, were 16^2 times farther from the anchor than they should have been. With icon-offset: [0, 0], this didn't matter, because the incorrectly large box would contain the (much smaller) correct box. But when there's an offset, it too gets scaled too much, and so we run out of luck.

[ChrisLoer]

🤦‍♂️ Good catch @anandthakker. This textPixelRatio has always been incorrect, but it used to be masked by us inverting the tileToViewport parameter. When I fixed that in #5913, I missed this.

[ChrisLoer]

Although this change is the simplest fix, it's worth noting that on gl-native we skipped this issue entirely by storing viewport coordinates in the GridIndex and just comparing the viewport-projected query directly against those coordinates instead of re-projecting tile coordinates the way we do in gl-js.