chore: updating slack invite links (#1788)

# Description
This PR updates the expired Slack invite link

## Type of Change

- [x] Bugfix
- [ ] New Feature
- [ ] Breaking Change
- [ ] Refactor
- [ ] Documentation
- [ ] Other (please describe)

## Checklist

- [x] I have read the [contributing
guidelines](/agntcy/repo-template/blob/main/CONTRIBUTING.md)
- [ ] Existing issues have been referenced (where applicable)
- [x] I have verified this change is not present in other open pull
requests
- [ ] Functionality is documented
- [ ] All code style checks pass
- [ ] New code contribution is covered by automated tests
- [ ] All new and existing tests pass

Signed-off-by: Aron Kerekes <arkereke@cisco.com>

Author: keraron

README.md

@@ -331,7 +331,7 @@ task lint
 
 - 📚 [Documentation](https://docs.agntcy.org/slim/overview)
 - 📖 [IETF Specification](https://datatracker.ietf.org/doc/draft-slim-protocol/)
-- 💬 [Slack Community](https://join.slack.com/t/agntcy/shared_invite/)
+- 💬 [Slack Community](https://join.slack.com/t/agntcy/shared_invite/zt-3xozr6nzq-i6LXv2P8l2kVW4_Prnny2w)
 - 🎥 [YouTube Channel](https://www.youtube.com/@agntcy-lf)
 
 ## License

docs/content/slim/slim-howto.md

@@ -429,7 +429,7 @@ You've installed SLIM! Here's what to do next:
 1. Read the [messaging layer documentation](./slim-data-plane.md)
 2. Explore the [example applications](https://github.com/agntcy/slim-bindings)
 3. Learn about [configuration options](./slim-data-plane-config.md)
-4. Join us on [Slack](https://join.slack.com/t/agntcy/shared_invite/zt-3hb4p7bo0-5H2otGjxGt9OQ1g5jzK_GQ)
+4. Join us on [Slack](https://join.slack.com/t/agntcy/shared_invite/zt-3xozr6nzq-i6LXv2P8l2kVW4_Prnny2w)
 
 ## Need Help?