deps: fix shim for `v8::Value::IntegerValue()`

This was introduced in 48d1335b. Previously, values such as
`undefined` would not be coerced properly because `NumberValue()`
returns `NaN` for them.

Refs: https://github.com/nodejs/node/pull/23158

PR-URL: https://github.com/nodejs/node/pull/23898


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>