Fix typespec_derive compilation tests #5370

Job	Run time
Get minimum supported rust version	15s
SDK docs	1m 32s
Lint	36s
Code Style	1m 2s
SDK Tests (stable, false)	4m 5s
E2E Tests (stable, false)	1m 15s
WASM Tests (stable, false)	2m 17s
SDK Tests (1.76, false)	4m 20s
WASM Tests (1.76, false)	1m 10s
SDK Tests (nightly, true)	2m 43s
WASM Tests (nightly, true)	2m 17s
E2E Tests (1.76, false)	2m 17s
E2E Tests (nightly, true)	1m 8s
	24m 57s

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