deps: trim the tokio feature set to the APIs in use

The runtime (multi-thread, for Runtime::new + block_on and task
spawning), time (retries, timeouts), sync (channels) and macros
(#[tokio::test]) cover every tokio:: path in the tree; 'full' also
pulled fs, io, net and process support nothing uses. Cargo.lock loses
the corresponding mio/signal deps if nothing else needs them.

Cargo.toml

@@ -19,7 +19,7 @@ reqwest = { version = "0.12.9", features = ["blocking", "json", "stream"] }
 git2 = "0.20.2"
 regex = "1"
 chrono = "0.4"
-tokio = { version = "1.41.1", features = ["full"] }
+tokio = { version = "1.41.1", features = ["rt-multi-thread", "macros", "time", "sync"] }
 sha2 = "0.10.8"
 sha1 = "0.10"
 md-5 = "0.10"