cln-plugin: Switch from env_logger to tracing-subscriber

This switches the logging implementation from using the `log`-facade
to using the `tracing-subscriber` instead. This allows us to also tap
into the tracing instrumentation if desired, which was not possible
with `log`.

Changelog-Changed cln-plugin: The logging adapter now uses tracing-subscriber allowing the `tracing` ecosystem to be used. No format changes.

plugins/Cargo.toml

@@ -15,14 +15,15 @@ path = "examples/cln-plugin-startup.rs"
 [dependencies]
 anyhow = "1.0.51"
 bytes = "1.1.0"
-log = { version = "0.4.14", features = ['std'] }
-serde = { version = "1.0.131", features = ["derive"] }
+log = { version = "^0.4", features = ['std'] }
+serde = { version = "^1", features = ["derive"] }
 serde_json = "1.0.72"
 tokio-util = { version = "0.7", features = ["codec"] }
 tokio = { version="1", features = ['io-std', 'rt', 'sync', 'macros', 'io-util'] }
 tokio-stream = "0.1"
 futures = "0.3"
-env_logger = "0.10"
+tracing-subscriber = { version = "^0.3", features = ["env-filter", "tracing"] }
+tracing = { version = "^0.1", features = ["async-await", "log"] }
 
 [dev-dependencies]
 tokio = { version = "1", features = ["macros", "rt-multi-thread", ] }