Bump tracing-subscriber from 0.3.19 to 0.3.20 (#350)

Bumps [tracing-subscriber](https://github.com/tokio-rs/tracing) from 0.3.19 to 0.3.20.
- [Release notes](https://github.com/tokio-rs/tracing/releases)
- [Commits](tokio-rs/tracing@tracing-subscriber-0.3.19...tracing-subscriber-0.3.20)

---
updated-dependencies:
- dependency-name: tracing-subscriber
  dependency-version: 0.3.20
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.toml

@@ -84,7 +84,7 @@ toml = "0.9.4"
 tracing = "0.1.41"
 tracing-appender = "0.2.3"
 tracing-slog = { git = "https://github.com/oxidecomputer/tracing-slog", default-features = false }
-tracing-subscriber = "0.3.19"
+tracing-subscriber = "0.3.20"
 uuid = { version = "1.17.0", features = ["serde"] }
 valuable = "0.1.1"
 v-api = { git = "https://github.com/oxidecomputer/v-api" }