fix: hack fix for contract tests on MacOS

fixes #19802

Contract Tests are failing with missing symbols runtime error on `MacOS` after `golang` version was upgraded to 1.20
A simple hack fix such a case is to use `go 1.19` only to build the status-go library that is used specifically for these integration tests.
Its ugly but it works and unblocks devs from running tests locally.

- execute `make test-contract` on MacOS and it should not fail.

not needed since this impacts only the integration tests.

- macOS

status: ready

nix/overlay.nix

@@ -61,6 +61,7 @@ in {
   };
   go = super.go_1_20;
   clang = super.clang_15;
+  buildGo19Package = super.buildGo19Package;
   buildGoPackage = super.buildGo120Package;
   buildGoModule = super.buildGo120Module;
   gomobile = (super.gomobile.overrideAttrs (old: {

nix/status-go/library/default.nix

@@ -1,8 +1,10 @@
-{ buildGoPackage
-# object with source attributes
-, meta, source}:
-
-buildGoPackage {
+{ stdenv, meta, source, buildGo119Package, buildGo120Package }:
+let
+# https://github.com/status-im/status-mobile/issues/19802
+# only for Darwin to fix Integration Tests failing with missing symbols on go 1.20
+buildGoPackageIntegrationTest = if stdenv.isDarwin then buildGo119Package else buildGo120Package;
+in
+buildGoPackageIntegrationTest {
   pname = source.repo;
   version = "${source.cleanVersion}-${source.shortRev}";