chore: update injective rpc URL (#465)

### Description

<!--
Summary of change.
Example: Add sepolia chain
-->

Update Injective RPC URL

### Backward compatibility

<!--
Are these changes backward compatible? Note that additions are backwards
compatible.

Yes/No
-->

Yes

### Testing

<!--
Have any new metadata configs and deployment addresses been used with
any Hyperlane tooling, such as the CLI?
-->
Manual

.changeset/short-windows-camp.md

@@ -0,0 +1,5 @@
+---
+'@hyperlane-xyz/registry': patch
+---
+
+update injective rpc URL

chains/injective/metadata.yaml

@@ -37,6 +37,7 @@ protocol: cosmos
 restUrls:
   - http: https://sentry.lcd.injective.network:443
 rpcUrls:
+  - http: https://injective-rpc.publicnode.com:443
   - http: https://sentry.tm.injective.network:443
 slip44: 118
 technicalStack: other