fix: rollback to 'slog' '2.7.0'

By running 'cargo update slog --precise 2.7.0'.
This is due to a mishandled deprecation in 'slog-scope' crate.
This PR once merged should fix the problem: slog-rs/scope#15

Author: jpraynaud

Cargo.lock

@@ -64,7 +64,7 @@ reqwest = { version = "0.12.24", default-features = false, features = ["json"] }
 semver = "1.0.27"
 serde = { version = "1.0.228", features = ["derive", "rc"] }
 serde_json = "1.0.145"
-slog = "2.8.2"
+slog = "2.7.0"
 slog-async = "2.8.0"
 slog-bunyan = "2.5.0"
 slog-term = "2.9.2"