[cli] Fix update command

[styfle]

The CLI name was updated but not the command.

This PR fixes the command to show the correct package name.

https://app.clubhouse.io/vercel/story/311/wrong-vercel-cli-package-name-being-rendered-in-the-update-message

[codecov]

Codecov Report

Merging #4353 into master will increase coverage by 0.10%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4353      +/-   ##
==========================================
+ Coverage   14.51%   14.61%   +0.10%     
==========================================
  Files         294      294              
  Lines       10513    10523      +10     
  Branches     1311     1313       +2     
==========================================
+ Hits         1526     1538      +12     
+ Misses       8905     8904       -1     
+ Partials       82       81       -1     

Impacted Files	Coverage Δ
src/util/get-update-command.ts	57.14% <0.00%> (+3.29%)	⬆️
src/util/pkg-name.ts	62.50% <0.00%> (+6.25%)	⬆️
src/util/metrics.ts	84.61% <0.00%> (+10.93%)	⬆️

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