Fix netlify test (#1398)

Netlify test was breaking due to a regression in prettyjson library.
The Netlify team fixed the cli, upgrading it to version 8.6.21 solves the issue

@pairs: @jlongtine

Signed-off-by: guillaume <guillaume.derouville@gmail.com>

pkg/alpha.dagger.io/universe.bats

@@ -43,7 +43,6 @@ setup() {
 }
 
 @test "netlify" {
-  skip "Temporary skip due to a regression in one of netlify's libraries"
   dagger -e netlify up
 }