boot-qemu.py: Eliminate single item container in _get_kernel_ver_tuple()

As pointed out by the refurb rules in ruff.toml:

  FURB171 Membership test against single-item container
     --> boot-qemu.py:130:12
      |
  129 |         utils.check_cmd(decomp_prog)
  130 |         if decomp_prog in ('gzip',):
      |            ^^^^^^^^^^^^^^^^^^^^^^^^
  131 |             decomp_cmd = [decomp_prog, '-c', '-d', self.kernel]
  132 |         else:
      |
  help: Convert to equality test

Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Author: nathanchance

boot-qemu.py

@@ -126,7 +126,7 @@ def _get_kernel_ver_tuple(self, decomp_prog: str) -> tuple[int, ...]:
             raise RuntimeError('No kernel set?')
 
         utils.check_cmd(decomp_prog)
-        if decomp_prog in ('gzip',):
+        if decomp_prog == 'gzip':
             decomp_cmd = [decomp_prog, '-c', '-d', self.kernel]
         else:
             raise RuntimeError(f"Unsupported decompression program ('{decomp_prog}')?")