src: use `As()` instead of `Cast()` for conversions
We mostly use As()
instead of Cast()
in our code, so this change
replaces the remaining calls to Cast()
with calls to As()
to maintain
the consistency.
Refs: https://github.com/nodejs/node/pull/39921/files#r702293529
Signed-off-by: Darshan Sen darshan.sen@postman.com