fix(csub): CSUB observations #3710

Job	Run time
Build	1m 55s
Check format	1m 15s
Smoke test	5m 45s
Test Intel fortran (ubuntu-22.04)	38m 28s
Extended testing (ubuntu-22.04)	18m 42s
Test Intel fortran (macos-13)	38m 43s
Extended testing (macos-13)	37m 12s
Test Intel fortran (windows-2022)	36m 1s
Test GNU fortran (macos-13, false)	36m 2s
Extended testing (windows-2022)	54m 32s
Test GNU fortran (macos-14, false)	34m 30s
Test GNU fortran (macos-14, true)	1h 0m 0s
Test GNU fortran (ubuntu-22.04, false)	32m 7s
Test GNU fortran (ubuntu-22.04, true)	1h 25m 2s
Test GNU fortran (windows-2022, false)	44m 31s
	8h 44m 45s

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