flint spkg-configure should test that flint is built with NTL support

[mezzarobba]

The NTL interface in Flint is an optional component that must be enabled at build time (at least with flint3; I haven't checked if this was the case with earlier versions), but Sage requires the NTL interface, so we should test that the system installation of flint is built with NTL support before linking to it.

[mkoeppe]

see also:

• Eliminate use of FLINT's NTL interface #32908

[mezzarobba]

On Thursday, 27 July 2023 17:10:49 CEST Matthias Köppe wrote: see also: - #32908

That would indeed be a better solution in the long term.

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-- Marc