PYTHON-5781 Coverage increase for `network_layer.py` #4574

Job	Run time
Build wheels for manylinux_x86_64	2m 20s
Build wheels for manylinux_s390x	15m 4s
Make SDist	48s
Build wheels for manylinux_ppc64le	13m 34s
Build wheels for manylinux_i686	2m 25s
Build wheels for macos	3m 22s
Build wheels for manylinux_aarch64	14m 7s
Build wheels for win_arm64	6m 12s
Build wheels for win32	6m 15s
Build wheels for win_amd6	4m 46s
Download Wheels	13s
	1h 9m 6s

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