MAINTAINERS: remove Johan Hedberg from Bluetooth subsystem

MAINTAINERS: remove Johan Hedberg from Bluetooth subsystem

We have not seen emails or tags from Johan in over 5 years,
and there is no recent mailing list activity.
Marcel Holtmann hasn't provided any tags in the Bluetooth
subsystem in over 5 years, but he is active on the Bluetooth
mailing list, providing informal review.
Luiz Augusto von Dentz is very active, handling essentially
all commits and reviews (12% coverage, but Luiz is the sole
active committer).

Subsystem BLUETOOTH SUBSYSTEM
  Changes 50 / 411 (12%)
  Last activity: 2026-02-23
  Marcel Holtmann <marcel@holtmann.org>:
  Johan Hedberg <johan.hedberg@gmail.com>:
  Luiz Augusto von Dentz <luiz.dentz@gmail.com>:
    Author 138d7eca445e 2026-02-23 00:00:00 164
    Committer 138d7eca445e 2026-02-23 00:00:00 361
    Tags 138d7eca445e 2026-02-23 00:00:00 362
  Top reviewers:
    [15]: pmenzel@molgen.mpg.de
    [8]: keescook@chromium.org
    [5]: willemb@google.com
    [4]: horms@kernel.org
    [3]: kuniyu@amazon.com
    [3]: luiz.von.dentz@intel.com
  INACTIVE MAINTAINER Johan Hedberg <johan.hedberg@gmail.com>

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Link: https://patch.msgid.link/20260303215339.2333548-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>