chore: remove outdated blog and release notes for version 2.4.0

Deleted the blog post and release notes for the 2.4.0 distributed runtime upgrade, and updated the README to link to the new release notes and blog URL for better accessibility and clarity.

Author: rithulkamesh

README.md

@@ -311,10 +311,6 @@ Full docs (with versioning and dark mode): **[docs.devsper.com](https://docs.dev
 | [Contributing](CONTRIBUTING.md) | Setup, testing, PR guidelines |
 | [FAQ](https://docs.devsper.com/docs/faq) | Common questions |
 
-### Blog
-
-- [Distributed Runtime Upgrade (v2.4.0)](devsper/docs/blog/2026-03-31-runtime-2-4-0.md)
-
 ---
 
 ## Attribution & Credits

devsper/docs/architecture/execution-model.md

@@ -8,5 +8,5 @@ That document is the source of truth for DAG execution, task state machine, HITL
 
 For the 2.4.0 distributed runtime upgrade summary, see:
 
-- `devsper/docs/releases/2.4.0.md`
-- `devsper/docs/blog/2026-03-31-runtime-2-4-0.md`
+- `https://docs.devsper.com/docs/release_notes`
+- `https://devsper.com/blog/distributed-runtime-upgrade-2-4-0`