Migrate the ruby buildpack and pkg/ruby from ctx.Exec(...) to ctx.ExecWithErr(...) to reduce the usage of os.Exit(...) and enable easier unit testing
Migrate the ruby buildpack and pkg/ruby from ctx.Exec(...) to ctx.ExecWithErr(...) to reduce the usage of os.Exit(...) and enable easier unit testing

PiperOrigin-RevId: 460486416
Change-Id: I3d929044f50cd656012c1fff31c2abf4927b6a69

GoogleCloudPlatform/buildpacks,GoogleCloudPlatform/buildpacks,GoogleCloudPlatform/buildpacks,GoogleCloudPlatform/buildpacks