feat(hosttailer): reduce fluent-bit log level to error

[aslafy-z]

Closes https://github.com/orgs/kube-logging/discussions/1916

[csatib02]

LGTM!

[pepov]

I came back here after the fact to double check what -qq does as I realized I haven't heard about that. I'm not sure where it was coming from, the only reference I found is from an internal lib in fluentbit that allows passing this argument multiple times, but fluentbit itself does not seem to behave differently with or without a second q:

docker run --rm fluent/fluent-bit:3.2.5 -o asdf -q
[2025/04/25 06:25:42] [error] [config] section 'asdf' tried to instance a plugin name that doesn't exist
[2025/04/25 06:25:42] [error] configuration file contains errors, aborting.

docker run --rm fluent/fluent-bit:3.2.5 -o asdf -qq
[2025/04/25 06:25:40] [error] [config] section 'asdf' tried to instance a plugin name that doesn't exist
[2025/04/25 06:25:40] [error] configuration file contains errors, aborting.

Overall -qq seems to behave the same and the original PR title is correct. No action needed from my side, just wanted to note here.