I keep trying to install various applications but I always get the same error and the app isn't installed.

The following error:

Processing triggers for initramfs-tools (0.140) ...
ln: failed to create hard link '/boot/initrd.img-5.10.0-kali7-rt-armmp.dpkg-bak' => '/boot/initrd.img-5.10.0-kali7-rt-armmp': Operation not permitted
cp: error writing '/boot/initrd.img-5.10.0-kali7-rt-armmp.dpkg-bak': No space left on device
dpkg: error processing package initramfs-tools (--configure):
installed initramfs-tools package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:

Always the same code for any install. "failed to create hard link, and error with the initramfs-tools". I'd appreciate any insight, thanks!!!