Update to upstream version 2.5.0

Detailed maintainer log:

• Update from 2.4.2 to 2.5.0
• Change sources from MASTER_SITES to GitHub
• Update version of Python dependency
• Remove CONFIGURE
• Add CFLAGS to find gmp.h
• Remov INSTALL_TARGET
• Update WWW in pkg-descr
• Update pkg-plist

The new version brings some enhancements and changes:

• New AGS global solver (#194), thanks to Vladislav Sovrasov
• New nlopt_get_numevals function providing a built-in evaluation counter (#160)
• New nlopt_get_errmsg function for more descriptive error messages
• Build system is converted from autotools to cmake (#49), thanks to Julien Schueller
• Plugins updated for recent Octave and Guile versions
• Various other build fixes and minor bug fixes

PR: 233497
Submitted by: rhurlin@gwdg.de (maintainer)