Formula update for Izhikevich_2007 Example #788

Job	Run time
Run linters with pre-commit	1m 32s
Determine Python versions	7s
Test building the documentation	2m 2s
Python 3.11 on ubuntu-20.04 (standalone: false, 32bit: false)	33m 55s
Python 3.11 on ubuntu-20.04 (standalone: false, 32bit: true)	29m 56s
Python 3.11 on ubuntu-20.04 (standalone: true, 32bit: false)	30m 30s
Python 3.11 on ubuntu-20.04 (standalone: true, 32bit: true)	36m 6s
Python 3.11 on windows-2019 (standalone: false, 32bit: false)	1h 20m 14s
Python 3.11 on windows-2019 (standalone: false, 32bit: true)	1h 18m 59s
Python 3.11 on windows-2019 (standalone: true, 32bit: false)	31m 27s
Python 3.11 on windows-2019 (standalone: true, 32bit: true)	33m 56s
Python 3.11 on macOS-11 (standalone: false, 32bit: false)	47m 4s
Python 3.11 on macOS-11 (standalone: false, 32bit: true)	45m 43s
Python 3.11 on macOS-11 (standalone: true, 32bit: false)	35m 42s
Python 3.11 on macOS-11 (standalone: true, 32bit: true)	29m 56s
Python 3.9 on ubuntu-20.04 (standalone: false, 32bit: false)	32m 31s
Python 3.9 on ubuntu-20.04 (standalone: true, 32bit: false)	36m 49s
Indicate completion to coveralls.io	13s
	9h 46m 42s

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