feat: don't run reboot with sudo on Linux with systemd

[SteveLauC]

What does this PR do

Based on the discussion in #861, on Linux with systemd, reboot can be invoked without sudo, this PR implements it.

Closes #861.

Standards checklist

• The PR title is descriptive.
• I have read CONTRIBUTING.md
• Optional: I have tested the code myself

For new steps

• Optional: Topgrade skips this step where needed
• Optional: The --dry-run option works with this step
• Optional: The --yes option works with this step if it is supported by
  the underlying command

If you developed a feature or a bug fix for someone else and you do not have the
means to test it, please tag this person here.

[SteveLauC]

cc @matkeith, here is a build for Linux with this patch included, welcome to give it a test.

[matkeith]

This did not work for me. I got a crash before the reboot phase
topgrade output.txt
output attached

[SteveLauC]

topgrade output.txt

Thanks for testing it! This crash is not related to this PR, it is caused by the waydroid step, please disable it and topgrade again :

$ ./topgrade --disable waydroid

[SteveLauC]

Regarding that waydroid issue, could you please provide the ouput of:

$ waydroid status

[matkeith]

here's the waydroid status. makes sense
matkeith@mattlaptop:~/Downloads$ waydroid status
ERROR: WayDroid is not initialized, run "waydroid init"

disabling waydroid let the update work but i was never prompted for a reboot to try it. output attached
topgrade output 2.txt

i'm running the topgrade file as an exe as my own user, i assume this is good enough?

[SteveLauC]

Use a shell that has not sudo privilege cached, i.e., haven't executed sudo recently, then run:

$ topgrade --dry-run --keep

Since it is a dry-run, you should see the following result, then type R to reboot your PC (Warning: it reboots your PC)

[matkeith]

that worked =) rebooted successfully!

[SteveLauC]

ERROR: WayDroid is not initialized, run "waydroid init"

Can you execute waydroid init, then run waydroid status again?

[matkeith]

sure.

here's the error

matkeith@mattlaptop:~$ sudo waydroid init
[sudo] password for matkeith: 
[19:14:27] ERROR: Failed to get system OTA channel: /lineage/waydroid_x86_64/VANILLA.json, error: -1
[19:14:27] See also: <https://github.com/waydroid>
Run 'waydroid log' for details.
matkeith@mattlaptop:~$ waydroid status
ERROR: WayDroid is not initialized, run "waydroid init"

i haven't used waydroid, only installed it in the possibility of using it in the future ...- but considering it isnt working i might just remove it from bazzite and simplify the issue

[SteveLauC]

Thanks for providing the output, I have created an issue in Topgrade for this: #869