additional packages version pinning

Author: isshaddad

docs/config/extensions/additionalPackages.mdx

@@ -19,7 +19,9 @@ export default defineConfig({
 });
 ```
 
-This allows you to include additional packages in the build that are not automatically included via imports. This is useful if you want to install a package that includes a CLI tool that you want to invoke in your tasks via `exec`. We will try to automatically resolve the version of the package but you can specify the version by using the `@` symbol:
+This allows you to include additional packages in the build that are not automatically included via imports. This is useful if you want to install a package that includes a CLI tool that you want to invoke in your tasks via `exec`. We will try to automatically resolve the version of the package but you can specify the version by using the `@` symbol.
+
+If you omit the version, the build may use a cached or older resolution. For reproducible builds, pin the exact version (e.g. `wrangler@1.19.0`).
 
 ```ts
 import { defineConfig } from "@trigger.dev/sdk";