Update the hostname in /boot/firmware/user-data

[civerachb-cpr]

Description

On Ubuntu Server 24.04 on Raspberry Pi editing the hostname in /etc/hostname alone is not sufficient to keep the new hostname to persist across reboots. /boot/firmware/user-data also needs to be updated with the hostname

Fixes #16.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Tested internally on cpr-raphael by using the turtlebot4_setup tool with this change.

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation

[hilary-luo]

As I was reviewing this I also noticed that in Jazzy, the hostname was added to /etc/turtlebot4/system but is never read or written to that location. Can we also remove that since it can be misleading.