`cv62` has no effect when `calt` is enabled.

[jpickwell]

The new @_ ligature only works when calt is disabled.

// @_ ligature works
"editor.fontLigatures": "'calt' 0, 'cv62' 1"

// @_ ligature does not work
"editor.fontLigatures": "'calt' 1, 'cv62' 1"

Applies to all of the styles (Argon, Krypton, Neon, Radon, and Xenon).