feat(ai): Add support for `AbortSignal` #23141

Job	Run time
Build the SDK	9m 7s
(bulk) Node.js and Browser (Chrome) Tests	5m 31s
(Firestore) Node.js and Browser (Chrome) Tests	23m 9s
(Auth) Node.js and Browser (Chrome) Tests	3m 1s
Firestore Integration Tests (memory)	4m 4s
Firestore Integration Tests (persistence)	9m 14s
	54m 6s

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