I confirm that source.list in /etc/apt/sources.list.d/debian-10.list isn't a problem to fix this. As you can see output from 'apt update', warning messages are pointing to gpgv gpgv1 gpgv2 GNU Privacy Guard.
After installing some debian packages 'apt update' output change to no public key, refer to attachment.
Err:1 http://security.debian.org buster/updates InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 112695A0E562B32A NO_PUBKEY 54404762BBB6E853
GNU Privacy Guard on my iMX8MN
root@imx8mn-ddr4-evk:~# gpgv --version
gpgv (GnuPG) 2.2.27
libgcrypt 1.8.4
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