Update dependencies (json-fortran and bspline-fortran)

Current versions:

• json-fortran: 8.2.5
• bspline-fortran: 5.3.0

Latest versions (at the time of writing):

• json-fortran: 9.0.3
• bspline-fortran: 7.4.1

Pending MRs:

• json-fortran: https://github.com/jacobwilliams/json-fortran/pull/586
• bspline-fortran: https://github.com/jacobwilliams/bspline-fortran/pull/93