Use C++-sryle static_cast, not C-style explicit cast

`uint32_t(param)` is actually functional notation of explicit casting,
not a direct constructor call. `uint32_t{param}` would be uniform
initialization syntax for a constructor call, but would not allow
narrowing from `uint64_t`. See issue #1904 for discussion.

src/diagnostics.cpp

@@ -76,5 +76,5 @@ std::pair<WarningState, std::optional<uint32_t>> getInitialWarningState(std::str
 		}
 	}
 
-	return {state, param > UINT32_MAX ? UINT32_MAX : uint32_t(param)};
+	return {state, param > UINT32_MAX ? UINT32_MAX : static_cast<uint32_t>(param)};
 }