Revert NamedTemporaryFile ContextManager in example notebooks #1890

Job	Run time
Translate scripts to notebooks	52s
Get list of notebooks	5s
Run notebook (direct_reconstruction.ipynb)	1m 32s
Run notebook (iterative_sense_reconstruction.ipynb)	1m 47s
Run notebook (pulseq_2d_radial_golden_angle.ipynb)	1m 50s
Run notebook (qmri_sg_challenge_2024_t1.ipynb)	58s
Run notebook (qmri_sg_challenge_2024_t2_star.ipynb)	1m 29s
Run notebook (regularized_iterative_sense_reconstruction.ipynb)	1m 30s
Run notebook (t1_mapping_with_grad_acq.ipynb)	1m 45s
Build and deploy documentation	1m 13s
deploy	0s
	13m 1s

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