Well, the debug output
org.kde.pim.kleopatra: No update for: "Gpg4win-3.1.15"
and, even more clearly,
GPGME 20211019T134123 07DC _gpgme_io_spawn: check: path=0x031deff0 argv[ 0] = C:\Program Files (x86)\GnuPG\bin\gpgconf.exe GPGME 20211019T134123 07DC _gpgme_io_spawn: check: path=0x031deff0 argv[ 1] = --query-swdb GPGME 20211019T134123 07DC _gpgme_io_spawn: check: path=0x031deff0 argv[ 2] = gpg4win GPGME 20211019T134123 07DC _gpgme_io_spawn: check: path=0x031deff0 argv[ 3] = Gpg4win-3.1.15
reveals that Kleopatra via gpgme ran the command
gpgconf --query-swdb gpg4win Gpg4win-3.1.15
i.e. that current is "Gpg4win-3.1.15".