Fix CHANGELOG.md PR link placeholder

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jeet1995

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -8,7 +8,7 @@
 
 #### Bugs Fixed
 Fixing an NPE caused due to boxed Boolean conversion. - See [PR 48656](https://github.com/Azure/azure-sdk-for-java/pull/48656/)
-* Fixed JVM-level `<clinit>` deadlock caused by `ImplementationBridgeHelpers.initializeAllAccessors()` eagerly loading all Cosmos SDK classes during concurrent class initialization. Each accessor getter now performs targeted class loading (via `Class.forName`) of only the specific class it needs, eliminating the circular initialization dependency chain that caused permanent thread deadlocks in multi-threaded applications and CI environments. - See [PR XXXX](https://github.com/Azure/azure-sdk-for-java/pull/XXXX)
+* Fixed JVM-level `<clinit>` deadlock caused by `ImplementationBridgeHelpers.initializeAllAccessors()` eagerly loading all Cosmos SDK classes during concurrent class initialization. Each accessor getter now performs targeted class loading (via `Class.forName`) of only the specific class it needs, eliminating the circular initialization dependency chain that caused permanent thread deadlocks in multi-threaded applications and CI environments. - See [PR 48667](https://github.com/Azure/azure-sdk-for-java/pull/48667)
 
 #### Other Changes