meson: add soversion with nix version to give SONAME to libs

[juhp]

Maybe this is more acceptable? It makes the soversion equal to the nix version.

See discussions in #13960 and #13979 etc

[juhp]

Hmm not good enough for MacOS: ld: malformed 32-bit x.y.z version number: 2.32.0pre

[juhp]

A simple workaround would be to remove the pre suffix. Do you have any others?

[Mic92]

What's the use case for having a more fine grined version here?

[juhp]

People were complaining that an integer SONAME version was misleading or giving expectations of API stability.
With this PR there is no such expectation, since SONAME will change with every minor release.

[juhp]

Fedora test build: https://koji.fedoraproject.org/koji/taskinfo?taskID=137146842

An alternative to .replace() could be .strip() - I am not fluent in meson.

[Mic92]

Tested and macOS / Linux look as expected.

% ls -la /nix/store/jk51fi97yrwl3grj97pv7gnl3ks3hxq0-nix-util-2.32.0pre/lib/
lrwxrwxrwx    - root 55 years  [libnixutil.so](http://libnixutil.so/) -> [libnixutil.so](http://libnixutil.so/).2.32.0
.r-xr-xr-x 2.0M root 55 years  [libnixutil.so](http://libnixutil.so/).2.32.0

 0x000000000000000e (SONAME)             Library soname: [[libnixutil.so](http://libnixutil.so/).2.32.0]

% ls -la
.r-xr-xr-x 4.8M root 55 years  libnixstore.2.32.0.dylib
lrwxrwxrwx    - root 55 years  libnixstore.dylib -> libnixstore.2.32.0.dylib

[xokdvium]

SGTM. Would be nice to deduplicate some of the code into nix-meson-build-support though

[juhp]

SGTM. Would be nice to deduplicate some of the code into nix-meson-build-support though

Okay I try a followup PR for that - good point

edit: see PR #14001