internal/task: fix two missed instances of extalloc

src/internal/task/gc_stack_chain.go

@@ -1,7 +1,5 @@
-//go:build (gc.conservative || gc.extalloc) && tinygo.wasm && !scheduler.coroutines
-// +build gc.conservative gc.extalloc
-// +build tinygo.wasm
-// +build !scheduler.coroutines
+//go:build gc.conservative && tinygo.wasm && !scheduler.coroutines
+// +build gc.conservative,tinygo.wasm,!scheduler.coroutines
 
 package task
 

src/internal/task/gc_stack_noop.go

@@ -1,5 +1,5 @@
-//go:build (!gc.conservative && !gc.extalloc) || !tinygo.wasm || scheduler.coroutines
-// +build !gc.conservative,!gc.extalloc !tinygo.wasm scheduler.coroutines
+//go:build !gc.conservative || !tinygo.wasm || scheduler.coroutines
+// +build !gc.conservative !tinygo.wasm scheduler.coroutines
 
 package task