Move scipy to optional requirements #2514

Job	Run time
linux-gallery-python3.12-upgraded-optional	1m 21s
windows-gallery-python3.12-upgraded-optional	1m 27s
linux-gallery-python3.9-minimum	38s
windows-gallery-python3.9-minimum	1m 7s
linux-python3.13-ros3	1m 21s
linux-python3.13-upgraded-optional	1m 31s
linux-python3.13-upgraded	1m 32s
linux-python3.9-minimum	1m 25s
macos-python3.13-upgraded-optional	1m 35s
macos-python3.9-minimum	1m 26s
windows-python3.9-minimum	1m 8s
windows-python3.13-upgraded-optional	1m 1s
Deploy pre-release from dev	0s
	15m 32s

Provide feedback