Aliases not being used while parsing contents of the `$ENV` file

[subnut]

Steps to reproduce

create $HOME/temp.env -

alias echo=_echo
_echo() { printf '%s\n' 'You are using the alias'; }
echo You are NOT using the alias

Now run ENV=$HOME/temp.env mrsh

Expected output

You are using the alias

Actual output

You are NOT using the alias