Debian-based OSI image build error due to missing apt-get command

[rezib]

Attempt to build a Debian based OSI image produces an error due to missing apt-get command in container:

$ fatbuildrctl build -a node-debian11 -s firehpc/envs --watch
Submitted node-debian11 build task a5f79411-d091-492e-bbb9-44b718be5ced
 ⚬ INFO: Running build a5f79411-d091-492e-bbb9-44b718be5ced
 ⚬ INFO: Extracting tarball /run/fatbuildr/fatbuildr-artifact-6v2d61ei.tar.xz in destination /var/lib/fatbuildr/workspaces/default/a5f79411-d091-492e-bbb9-44b718be5ced
 ⚬ INFO: Building the OS image based node-debian11
‣ Changing ownership of output file /var/lib/fatbuildr/workspaces/default/a5f79411-d091-492e-bbb9-44b718be5ced/debian~bullseye to user root…
‣ Changed ownership of /var/lib/fatbuildr/workspaces/default/a5f79411-d091-492e-bbb9-44b718be5ced/debian~bullseye
‣ Removing output files…
‣ Detaching namespace
‣ Setting up temporary workspace.
‣ Temporary workspace set up in /var/tmp/mkosi-b25g1iz7
‣ Running second (final) stage…
‣  Mounting image…
‣   Setting up basic OS tree…
‣   Mounting Package Cache
‣    Installing Debian…
W: Cannot check Release signature; keyring file not available /usr/share/keyrings/debian-archive-keyring.gpg
I: Retrieving InRelease 
I: Retrieving Packages 
I: Validating Packages 
I: Resolving dependencies of required packages...
...
I: Unpacking openssl...
I: Configuring the base system...
I: Configuring openssl...
I: Configuring ca-certificates...
I: Configuring ca-certificates...
I: Base system installed successfully.
‣     Mounting API VFS…
‣ Error: /usr/bin/apt-get not found in PATH.