nwchem: make sure to link both single and double precision fftw libraries. (#39333)

With the previous version of the recipe I would get linking errors due
to missing `-lfftw3f`.

Co-authored-by: Cristian Di Pietrantonio <cdipietrantonio@pawsey.org.au>

var/spack/repos/builtin/packages/nwchem/package.py

@@ -59,7 +59,7 @@ def install(self, spec, prefix):
         scalapack = spec["scalapack"].libs
         lapack = spec["lapack"].libs
         blas = spec["blas"].libs
-        fftw = spec["fftw-api"].libs
+        fftw = spec["fftw-api:double,float"].libs
         # see https://nwchemgit.github.io/Compiling-NWChem.html
         args = []
         args.extend(