README.md: renew slack invitation link

Signed-off-by: Takahiro Itazuri <itazur@amazon.com>

Author: zulinx86

README.md

@@ -177,7 +177,7 @@ You can get in touch with the Firecracker community in the following ways:
 
 - Security-related issues, see our [security policy document](SECURITY.md).
 - Chat with us on our
-  [Slack workspace](https://join.slack.com/t/firecracker-microvm/shared_invite/zt-1dfaeyjf9-Ct6BwunYXfx_E13Qg2pIxw).
+  [Slack workspace](https://join.slack.com/t/firecracker-microvm/shared_invite/zt-1fecwrorm-x5URTlOzBR2fExTU2mWfug)
   _Note: most of the maintainers are on a European time zone._
 - Open a GitHub issue in this repository.
 - Email the maintainers at