sbang: vendor sbang

`sbang` now lives at https://github.com/spack/sbang, and it has its own
test suite that's more extensive than what's in Spack. We'll leave sbang
tests to sbang from now on, and just vendor `bin/sbang` directly.
Remaining `sbang` tests have to do with patching files, not with
`sbang`'s functionality.

This update also fixes a bug with `sbang` and multiple command line
arguments that was introduced in #19529. See:
  * https://github.com/spack/sbang/pull/1
  * https://github.com/spack/sbang/pull/2

- [x] include latest `sbang` from https://github.com/spack/sbang
- [x] remove old `sbang` tests from Spack
- [x] update `COPYRIGHT` and `cmd/license.py`

lib/spack/spack/cmd/license.py

@@ -32,7 +32,6 @@
     # spack scripts
     r'^bin/spack$',
     r'^bin/spack-python$',
-    r'^bin/sbang$',
 
     # all of spack core
     r'^lib/spack/spack/.*\.py$',

lib/spack/spack/test/sbang.py

@@ -217,68 +217,3 @@ def test_install_sbang(install_mockery):
     # install again and make sure sbang is still fine
     sbang.install_sbang()
     check_sbang_installation()
-
-
-def test_sbang_fails_without_argument():
-    sbang = which(spack.paths.sbang_script)
-    sbang(fail_on_error=False)
-    assert sbang.returncode == 1
-
-
-@pytest.mark.parametrize("shebang,returncode,expected", [
-    # perl, with and without /usr/bin/env
-    ("#!/path/to/perl",         0, "/path/to/perl -x"),
-    ("#!/usr/bin/env perl",     0, "/usr/bin/env perl -x"),
-
-    # perl -w, with and without /usr/bin/env
-    ("#!/path/to/perl -w",      0, "/path/to/perl -w -x"),
-    ("#!/usr/bin/env perl -w",  0, "/usr/bin/env perl -w -x"),
-
-    # ruby, with and without /usr/bin/env
-    ("#!/path/to/ruby",         0, "/path/to/ruby -x"),
-    ("#!/usr/bin/env ruby",     0, "/usr/bin/env ruby -x"),
-
-    # python, with and without /usr/bin/env
-    ("#!/path/to/python",       0, "/path/to/python"),
-    ("#!/usr/bin/env python",   0, "/usr/bin/env python"),
-
-    # php with one-line php comment
-    ("<?php #!/usr/bin/php ?>", 0, "/usr/bin/php"),
-
-    # simple shell scripts
-    ("#!/bin/sh",               0, "/bin/sh"),
-    ("#!/bin/bash",             0, "/bin/bash"),
-
-    # error case: sbang as infinite loop
-    ("#!/path/to/sbang",        1, None),
-    ("#!/usr/bin/env sbang",    1, None),
-
-    # lua
-    ("--!/path/to/lua",         0, "/path/to/lua"),
-
-    # node
-    ("//!/path/to/node",        0, "/path/to/node"),
-])
-def test_sbang_with_specific_shebang(
-        tmpdir, shebang, returncode, expected):
-
-    script = str(tmpdir.join("script"))
-
-    # write a script out with <shebang> on second line
-    with open(script, "w") as f:
-        f.write("#!/bin/sh {sbang}\n{shebang}\n".format(
-            sbang=spack.paths.sbang_script,
-            shebang=shebang
-        ))
-    fs.set_executable(script)
-
-    # test running the script in debug, which prints what would be executed
-    exe = which(script)
-    out = exe(output=str, fail_on_error=False, env={"SBANG_DEBUG": "1"})
-
-    # check error status and output vs. expected
-    assert exe.returncode == returncode
-
-    if expected is not None:
-        expected += " " + script
-        assert expected == out.strip()