installation: linux: debian: fix url in sources list

[Xata]

Hello!
I was following the documentation to install Fluent Bit on Debian. I saw that in the ## Update your sources lists section the line was referencing Ubuntu not Debian, which would cause the sudo apt-get update section to error out with:

Ign:8 https://packages.fluentbit.io/ubuntu/bookworm bookworm InRelease          
Hit:5 http://mirrors.digitalocean.com/debian bookworm-backports InRelease
Err:9 https://packages.fluentbit.io/ubuntu/bookworm bookworm Release
  404  Not Found [IP: 172.67.175.82 443]
Reading package lists... Done
E: The repository 'https://packages.fluentbit.io/ubuntu/bookworm bookworm Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

By changing the line in the documentation from:

echo "deb [signed-by=/usr/share/keyrings/fluentbit-keyring.gpg] https://packages.fluentbit.io/ubuntu/$codename $codename main" | sudo tee /etc/apt/sources.list.d/fluent-bit.list

To this (replaced ubuntu with debian):

echo "deb [signed-by=/usr/share/keyrings/fluentbit-keyring.gpg] https://packages.fluentbit.io/debian/$codename $codename main" | sudo tee /etc/apt/sources.list.d/fluent-bit.list

That part of the steps now works.

[alexakreizinger]

thanks for catching (and fixing) that :)