Fix typo in README for 'allow_net' usage

Corrected a typo in the README regarding 'allow_net'.

Author: NoRaincheck

README.md

@@ -36,7 +36,7 @@ LangChain Sandbox provides a secure environment for executing untrusted Python c
 
 
 > [!warning]
-> Use `alllow_net` to limit the network requests that can be made by the sandboxed code to avoid SSRF attacks
+> Use `allow_net` to limit the network requests that can be made by the sandboxed code to avoid SSRF attacks
 > https://docs.deno.com/runtime/fundamentals/security/#network-access
 
 ```python