Merge pull request #1 from rust-iot/dependabot/cargo/defmt-0.3

Update defmt requirement from 0.2 to 0.3

Author: henrikssn

Cargo.toml

@@ -34,7 +34,7 @@ modular-bitfield = "0.11.0"
 nb = {version = "1", optional = true}
 void = {version = "1", optional = true}
 
-defmt = { version = "0.2", optional = true}
+defmt = { version = "0.3", optional = true}
 log = { version = "0.4", default-features = false, optional = true }
 
 [dev-dependencies]