Update feign.version to 13.10 in pom.xml

[AhsanSheraz]

This PR updates <feign.version> to 13.10.

Reason: the current dependency chain pulls commons-fileupload:1.5 transitively through feign-form-spring, which is affected by CVE-2025-48976 (HIGH). The fixed version is 1.6.0.

Dependency path:

spring-cloud-openfeign-core
 -> feign-form-spring
 -> commons-fileupload:1.5

Updating the managed OpenFeign version fixes this in the dependency management layer and avoids requiring downstream consumers to override commons-fileupload directly.

I also validated the changes locally & all passed successfully against multiple JDK versions below:

• Java 17
• Java 21
• Java 25

Fixes #1342

[ryanjbaxter]

We can only upgrade patches for our dependencies on this branch

[AhsanSheraz]

We can only upgrade patches for our dependencies on this branch

@ryanjbaxter Any plans to fix high CVE's coming from commons-fileupload:1.5? Or should we migrate to https://docs.spring.io/spring-framework/reference/integration/rest-clients.html#rest-http-service-client

[ryanjbaxter]

The CVE is already addressed in the version we are using according to openfeign https://github.com/OpenFeign/feign/releases/tag/13.6.1