after upgrade:
Jan  2 20:59:40 debian-home kernel: [   12.651966] nvidia: loading
out-of-tree module taints kernel.
Jan  2 20:59:40 debian-home kernel: [   12.651981] nvidia: module license
'NVIDIA' taints kernel.
Jan  2 20:59:40 debian-home kernel: [   12.651983] Disabling lock debugging
due to kernel taint
Jan  2 20:59:40 debian-home kernel: [   12.668265] nvidia: module
verification failed: signature and/or required key missing - tainting kernel

I'm use:
Debian version: 11.2(stable)
Architecture: amd64

Yes. That's expected when using a proprietary out-of-tree kernel module.
I don't see a bug here.
(The last message is about signing the kernel and its modules, but
that's something requiring local configuration, nothing the nvidia
packages are responsible for.)

Andreas