Support conflict token retry loop for schedule updates

[chris-olszewski]

Is your feature request related to a problem? Please describe.

No SDK passes or retries on the conflict token for schedule updates. The server returns FailedPrecondition("mismatched conflict token") as of temporalio/temporal#8474.

Describe the solution you'd like

SDKs should:

1. Pass the conflict token from DescribeSchedule in UpdateSchedule requests
2. Retry the describe-modify-update loop on FailedPrecondition with "mismatched conflict token"

Additional context

Per-SDK Tickets

• Go - [go] Support conflict token retry loop for schedule updates sdk-go#2233
• Java - [java] Support conflict token retry loop for schedule updates sdk-java#2809
• TypeScript - [typescript] Support conflict token retry loop for schedule updates sdk-typescript#1967
• Python - [python] Support conflict token retry loop for schedule updates sdk-python#1367
• .NET - [.net] Support conflict token retry loop for schedule updates sdk-dotnet#624
• Ruby - [ruby] Support conflict token retry loop for schedule updates sdk-ruby#401
• Rust - [core] Support conflict token retry loop for schedule updates sdk-core#1157
• PHP - [php] Support conflict token retry loop for schedule updates sdk-php#729