tree-wide: replace uses of splitString "." with lib.versions

Quoting from the splitString docstring:

   NOTE: this function is not performant and should never be used.

This replaces trivial uses of splitString for splitting version
strings with the (potentially builtin) splitVersion.

pkgs/applications/science/logic/yices/default.nix

@@ -28,7 +28,7 @@ stdenv.mkDerivation rec {
   # Includes a fix for the embedded soname being libyices.so.2.5, but
   # only installing the libyices.so.2.5.x file.
   installPhase = let
-    ver_XdotY = builtins.concatStringsSep "." (stdenv.lib.take 2 (stdenv.lib.splitString "." version));
+    ver_XdotY = stdenv.lib.versions.majorMinor version;
   in ''
       make install LDCONFIG=true
       ln -sfr $out/lib/libyices.so.{${version},${ver_XdotY}}