Stop building and shipping openspecfun (JuliaLang/julia#23598)

LICENSE.md

@@ -54,8 +54,6 @@ their own licenses:
 - [ARPACK](http://www.caam.rice.edu/software/ARPACK/RiceBSD.txt#LICENSE) [BSD-3]
 - [DSFMT](http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/LICENSE.txt) [BSD-3]
 - [OPENLIBM](https://github.com/JuliaLang/openlibm/blob/master/LICENSE.md) [MIT, BSD-2, ISC]
-- [OPENSPECFUN](https://github.com/JuliaLang/openspecfun) [MIT, public domain]
-- [FADDEEVA](http://ab-initio.mit.edu/Faddeeva) [MIT]
 - [GMP](http://gmplib.org/manual/Copying.html#Copying) [LGPL3+ or GPL2+]
 - [LIBGIT2](https://github.com/libgit2/libgit2/blob/development/COPYING) [GPL2+ with unlimited linking exception]
 - [CURL](https://curl.haxx.se/docs/copyright.html) [MIT/X derivative]