audio/rubberband: Update to 1.9.1

Changes in Rubber Band v1.9.1

• Switch build system from Makefiles and Visual Studio project to Meson/Ninja for all platforms. There are still Makefiles and VS projects included in otherbuilds/ for those who wish to use them to build the static library directly
• Make various fixes to improve sound quality when pitch-shifting dynamically in real-time (requires libsamplerate)
• Fix floating-point exception when a very very long stretch factor is presented
• Move the two directories that together provide the .NET interface (rubberband-sharp and rubberband-dll) into their own subdir (dotnet)
• Ensure the library builds and runs correctly on ARM Mac (Apple Silicon, M1), and also on Windows using the Visual C++ Clang front-end

The API is unchanged and the library is binary compatible with version
1.7.

PR: 255965
Approved by: acm (maintainer, timeout)

Co-authored-by: Joseph Mingrone <jrm@FreeBSD.org>