Hardcoded shebang doesn't work on NixOS

[MatteoJoliveau]

Hi! I use a Linux distro called NixOS which has a very particular filesystem layout and package management.
Tl;dr, executable are not found in the usual locations (e.g. /bin or /usr/local/bin) but must be sourced from PATH. The only executable in a standard location is /usr/bin/env.

This means that the scripts cargo-zigbuild generates do not work on NixOS because the shebang declare #!/bin/bash as the interpreter, which cannot be found.

Would you be willing to accept a PR that changes those headers to #!/usr/bin/env bash? This will work on all Linux distros and, in addition to supporting NixOS as a platform, would also cover any system with non-standard or customized bash installs.

[messense]

Sure!

[messense]

Released in v0.5.1.