gh-145335: Skip Emscripten for os.execve() test (#145528)

Emscripten's os.execve() always fails with ENOEXEC.

Co-authored-by: Victor Stinner <vstinner@python.org>

Author: hoodmane

Lib/test/test_os/test_os.py

@@ -2824,7 +2824,8 @@ def test_negative_fd_ebadf(self, fd):
                     func(*args)
                 self.assertEqual(ctx.exception.errno, errno.EBADF)
 
-        if hasattr(os, "execve") and os.execve in os.supports_fd:
+        if (hasattr(os, "execve") and os.execve in os.supports_fd
+            and support.has_subprocess_support):
             # glibc fails with EINVAL, musl fails with EBADF
             with self.assertRaises(OSError) as ctx:
                 os.execve(fd, [sys.executable, "-c", "pass"], os.environ)