Fix GSL to work with vcpkg installation (used in test_latest.yml) #983

Job	Run time
Determine Python versions	6s
Run linters with pre-commit	1m 2s
Test building the documentation	1m 34s
Python 3.12 on ubuntu-22.04 (standalone: false, 32bit: false)	1h 8m 56s
Python 3.12 on ubuntu-22.04 (standalone: false, 32bit: true)	1h 9m 6s
Python 3.12 on ubuntu-22.04 (standalone: true, 32bit: false)	21m 3s
Python 3.12 on ubuntu-22.04 (standalone: true, 32bit: true)	20m 32s
Python 3.12 on windows-2022 (standalone: false, 32bit: false)	1h 38m 53s
Python 3.12 on windows-2022 (standalone: false, 32bit: true)	1h 37m 21s
Python 3.12 on windows-2022 (standalone: true, 32bit: false)	28m 48s
Python 3.12 on windows-2022 (standalone: true, 32bit: true)	26m 55s
Python 3.12 on macOS-12 (standalone: false, 32bit: false)	1h 39m 19s
Python 3.12 on macOS-12 (standalone: false, 32bit: true)	1h 12m 58s
Python 3.12 on macOS-12 (standalone: true, 32bit: false)	24m 55s
Python 3.12 on macOS-12 (standalone: true, 32bit: true)	32m 16s
Python 3.12 on macOS-14 (standalone: false, 32bit: false)	48m 42s
Python 3.12 on macOS-14 (standalone: false, 32bit: true)	44m 4s
Python 3.12 on macOS-14 (standalone: true, 32bit: false)	12m 30s
Python 3.12 on macOS-14 (standalone: true, 32bit: true)	12m 16s
Python 3.10 on ubuntu-22.04 (standalone: false, 32bit: false)	1h 1m 40s
Python 3.10 on ubuntu-22.04 (standalone: true, 32bit: false)	19m 16s
Indicate completion to coveralls.io	10s
	14h 22m 22s

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