docs: update url service status badges

Author: bot-anik

README.md

@@ -38,7 +38,7 @@ src="assets/linktree.webp" style="width:15px;height:15px;"> [Linktree](https://l
 
 | Thanks To                                | Explorer | URL                                           | Status |
 |------------------------------------------|----------|-----------------------------------------------|--------|
-| [OKP4](https://github.com/okp4)          | Ping Pub | <https://explore.okp4.network>                | ✅     |
+| [OKP4](https://github.com/okp4)          | Ping Pub | <https://explore.okp4.network>                | ❌     |
 | [BccNodes](https://github.com/BccNodes/) | Ping Pub | <https://explorer.bccnodes.com/okp4>          | ✅     |
 | [Ping Pub](https://github.com/ping-pub/) | Ping Pub | <https://ping.pub/okp4%20testnet?testnet>     | ✅     |
 | [L0vd](https://github.com/L0vd)          | Ping Pub | <https://explorers.l0vd.com/okp4-testnet>     | ✅     |