MetaCall Core clone is not efficient and it does not have a configurable version

[viferga]

In this line:
https://github.com/metacall/builder/blob/989a6ae8df2e1c1a77e62365f11e03263dedab45/main.go#L173

Use this instead:

git clone --depth 1 --single-branch --branch=develop https://github.com/metacall/core.git

And if the user specifies a different version:

git clone --depth 1 --single-branch --branch=v0.5.2 https://github.com/metacall/core.git

Set the version CLI option as develop by default.