[LyX/2.5.x] Update ja.po

[Koji Yokota]

commit 2f2e08e1ba5429688b110fc2a16c39d1e223f66f
Author: Koji Yokota <yokota at lyx.org>
Date:   Sat Jul 4 14:22:50 2026 +0900

    Update ja.po

 po/ja.gmo |  Bin 751168 -> 751819 bytes
 po/ja.po  | 2519 +++++++++++++++++++++++++++++--------------------------------
 2 files changed, 1217 insertions(+), 1302 deletions(-)