[BIT] fix unexpected inplace squeeze_ in paddle.signal.istft #4087

Job	Run time
Clone-linux / Clone Paddle	3m 49s
PR-CI-Coverage / Coverage build	46m 50s
PR-CI-Inference / Check bypass for inference / Check bypass	3s
PR-CI-SOT / Check bypass for SOT / Check bypass	3s
PR-CI-SOT / Build and Test	2h 51m 4s
PR-CI-Inference / Build	29m 56s
PR-CI-Inference / Test	7m 34s
PR-CI-Coverage / Coverage test	5m 0s
	4h 24m 19s

Provide feedback