fix(sdk): drop invalid status field from mockChatAgent OOM-retry test

The TaskRunExecutionAttempt type only includes `number` and `startedAt`.
The `status: "EXECUTING"` field I included was invalid. tsc passed on
my local test runner (vitest uses esbuild, not tsc) but the typecheck
CI step caught it. Drop the field, keeping the override to just the two
supported keys.

Author: ericallam

packages/trigger-sdk/test/mockChatAgent.test.ts

@@ -1526,7 +1526,7 @@ describe("mockChatAgent", () => {
       const harness = mockChatAgent(agent, {
         chatId: "oom-retry-skip",
         taskContext: {
-          ctx: { attempt: { number: 2, startedAt: new Date(0), status: "EXECUTING" } },
+          ctx: { attempt: { number: 2, startedAt: new Date(0) } },
         },
       });
       try {