Update d3 dependency to 7.1.1 in package.json

[juba]

I just upgraded Plot to 0.2.8, and got an error when trying to bundle it :

ERROR in ./node_modules/@observablehq/plot/src/transforms/map.js 54:9-13
export 'rank' (imported as 'rank') was not found in 'd3' 

My d3 version was 7.0.1. After upgrading to the latest 7.1.1 version, the error went away.

As the rank function seems to be quite new, maybe the d3 dependency should be set to 7.1.1 in package.json ?

Thanks !