Deno's module loader currently strips a shebang if a module file
starts with one. However, this is no longer necessary, since there is
a stage-3 TC39 that adds support for shebangs (or "hashbangs") to the
language (https://github.com/tc39/proposal-hashbang), and V8, `tsc`
and `swc` all support it.
Furthermore, stripping shebangs causes a correctness bug with JSON
modules, since a JSON file with a shebang should not parse as a JSON
module, yet it does with this stripping. This change fixes this.
