Make sure to include kali-linux-firmware in the installer images

Usually it's pulled in via dependency (as it's a dep of
kali-linux-headless IIRC itself a dep of kali-linux-default). But that's
not the case for Kali Purple, as it doesn't depend on
kali-linux-default.

Furthermore, kali-linux-firmware is now installed in all cases by
tasksel, so we must make sure it's there, instead of relying on
metapackage's dependencies.

Hopefully it will fix:
- https://gitlab.com/kalilinux/kali-purple/documentation/-/issues/8
- https://gitlab.com/kalilinux/kali-purple/documentation/-/issues/11

kali-config/installer-default/packages

@@ -7,6 +7,7 @@
 # You can customize the set of Kali metapackages (groups of tools) available
 # in the installer ISO.
 # For the complete list see: https://tools.kali.org/kali-metapackages
+kali-linux-firmware
 kali-linux-core
 kali-tools-top10
 kali-linux-default

kali-config/installer-everything/packages

@@ -4,6 +4,7 @@
 # You can customize the set of Kali metapackages (groups of tools) available
 # in the installer ISO.
 # For the complete list see: https://tools.kali.org/kali-metapackages
+kali-linux-firmware
 kali-linux-core
 kali-tools-top10
 kali-linux-default

kali-config/installer-purple/packages

@@ -4,6 +4,7 @@
 # You can customize the set of Kali metapackages (groups of tools) available
 # in the installer ISO.
 # For the complete list see: https://tools.kali.org/kali-metapackages
+kali-linux-firmware
 kali-system-gui
 kali-themes-purple  # temporary, until we do it a better way