fix(api): bump minimum version of tonic

Change the minimum version of tonic from 0.12 to 0.12.3. This fixes
compilation in downstream projects with old lock files, since the
generated code now uses a constant only present in tonic 0.12.3.

Closes tokio-rs#592

Author: divergentdave

console-api/Cargo.toml

@@ -29,7 +29,7 @@ keywords = [
 transport = ["tonic/transport"]
 
 [dependencies]
-tonic = { version = "0.12", default-features = false, features = [
+tonic = { version = "0.12.3", default-features = false, features = [
     "prost",
     "codegen",
     "transport",