Remove the unused log::sink module

The `LogSink` trait got introduced in 7188fc9 to abstract log sinks
(destinations). A `FileSink` implementation was added in 3ff4fee to
write logs to a file and optional support for the orchestrator was added
in d35bf6e.

It isn't needed anymore since the implementation in da12a96 stopped
relying on `FileSink` or rather `FileLogSinkFactory`.
The `log::filesink` module was then removed in `bfe392e` but `log::sink`
never got cleanup up. I noticed this now because `rustc 1.75.0-beta.1`
detected the unused import: `sink::*` in `src/log/mod.rs:18:9` via the
`unused_imports` lint.

Signed-off-by: Michael Weiss <michael.weiss@atos.net>

src/log/mod.rs

@@ -14,7 +14,4 @@ pub use parser::*;
 mod item;
 pub use item::*;
 
-mod sink;
-pub use sink::*;
-
 mod util;