This is happening to my NVIDIA module build with kernel 5.10.12 as well.

root@jaxel:~# dpkg-reconfigure nvidia-dkms-460 
Removing all DKMS Modules
Done.
update-initramfs: deferring update (trigger activated)
update-initramfs: Generating /boot/initrd.img-5.9.16-050916-generic
INFO:Enable nvidia
DEBUG:Parsing /usr/share/ubuntu-drivers-common/quirks/dell_latitude
DEBUG:Parsing /usr/share/ubuntu-drivers-common/quirks/lenovo_thinkpad
DEBUG:Parsing /usr/share/ubuntu-drivers-common/quirks/put_your_quirks_here
Loading new nvidia-460.39 DKMS files...
Building for 5.9.16-050916-generic 5.10.12-051012-generic
Building for architecture x86_64
Building initial module for 5.9.16-050916-generic
Secure Boot not enabled on this system.
Done.

nvidia.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.9.16-050916-generic/updates/dkms/

nvidia-modeset.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.9.16-050916-generic/updates/dkms/

nvidia-drm.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.9.16-050916-generic/updates/dkms/

nvidia-uvm.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.9.16-050916-generic/updates/dkms/

depmod...

DKMS: install completed.
Building initial module for 5.10.12-051012-generic
ERROR (dkms apport): kernel package linux-headers-5.10.12-051012-generic is not supported
Error! Bad return status for module build on kernel: 5.10.12-051012-generic (x86_64)
Consult /var/lib/dkms/nvidia/460.39/build/make.log for more information.

--- /var/lib/dkms/nvidia/460.39/build/make.log

make -f ./scripts/Makefile.modpost
  sed 's/ko$/o/' /var/lib/dkms/nvidia/460.39/build/modules.order | scripts/mod/modpost  -a   -o /var/lib/dkms/nvidia/460.39/build/Module.symvers -e -i Module.symvers   -T -
make -f ./scripts/Makefile.modfinal
make[3]: *** No rule to make target 'scripts/module.lds', needed by '/var/lib/dkms/nvidia/460.39/build/nvidia-drm.ko'.  Stop.
make[3]: *** Waiting for unfinished jobs....
  cc -Wp,-MMD,/var/lib/dkms/nvidia/460.39/build/.nvidia-drm.mod.o.d  -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/9/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -fmacro-prefix-map=./= -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Wno-format-security -std=gnu89 -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -m64 -falign-jumps=1 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mpreferred-stack-boundary=3 -mskip-rax-setup -mtune=generic -mno-red-zone -mcmodel=kernel -DCONFIG_X86_X32_ABI -Wno-sign-compare -fno-asynchronous-unwind-tables -mindirect-branch=thunk-extern -mindirect-branch-register -fno-jump-tables -fno-delete-null-pointer-checks -Wno-frame-address -Wno-format-truncation -Wno-format-overflow -Wno-address-of-packed-member -O2 --param=allow-store-data-races=0 -Wframe-larger-than=1024 -fstack-protector-strong -Wno-unused-but-set-variable -Wimplicit-fallthrough -Wno-unused-const-variable -fno-omit-frame-pointer -fno-optimize-sibling-calls -pg -mrecord-mcount -mfentry -DCC_USING_FENTRY -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-stringop-truncation -Wno-array-bounds -Wno-stringop-overflow -Wno-restrict -Wno-maybe-uninitialized -fno-strict-overflow -fno-stack-check -fconserve-stack -Werror=date-time -Werror=incompatible-pointer-types -Werror=designated-init -fcf-protection=none -Wno-packed-not-aligned  -DMODULE  -DKBUILD_BASENAME='"nvidia_drm.mod"' -DKBUILD_MODNAME='"nvidia_drm"' -c -o /var/lib/dkms/nvidia/460.39/build/nvidia-drm.mod.o /var/lib/dkms/nvidia/460.39/build/nvidia-drm.mod.c
make[2]: *** [scripts/Makefile.modpost:117: __modpost] Error 2
make[1]: *** [Makefile:1709: modules] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.10.12-051012-generic'