Add Fortran build stuff and tests #17

Job	Run time
tests-resolution-strategies (ubuntu-latest, lowest-direct, 3.9)	20s
mypy (ubuntu-latest, 3.9)	26s
imports-without-extras (ubuntu-latest, 3.13)	17s
check-build (ubuntu-latest, 3.11)	20s
imports-without-extras (ubuntu-latest, 3.11)	19s
tests (ubuntu-latest, 3.11)	17s
imports-without-extras (ubuntu-latest, 3.12)	19s
tests (ubuntu-latest, 3.9)	19s
check-dependency-licences (ubuntu-latest, 3.11)	19s
tests (ubuntu-latest, 3.13)	19s
tests (ubuntu-latest, 3.10)	20s
urls	13s
docs (ubuntu-latest, 3.11)	20s
tests-without-extras (ubuntu-latest, 3.11)	24s
imports-without-extras (ubuntu-latest, 3.10)	19s
tests (ubuntu-latest, 3.12)	17s
imports-without-extras (ubuntu-latest, 3.9)	22s
	5m 30s

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