fix: unconditional process reference

process does not exist in the browser and therefore throws an error if
one tries to create a client in the browser.
Fix it in a way that's compatible with any (future) engine that doesn't
have a process global.

src/lib/constants.ts

@@ -3,7 +3,7 @@ import { DeepgramClientOptions } from "./types/DeepgramClientOptions";
 import { FetchOptions } from "./types/Fetch";
 import { version } from "./version";
 
-export const NODE_VERSION = process.versions.node;
+export const NODE_VERSION = process?.versions.node || "Unknown";
 
 export const DEFAULT_HEADERS = {
   "Content-Type": `application/json`,