While, as Ronald notes, it would be nice to fully support weak linking so that building Python on macOS 10.n with a deployment target for 10.m where m < n so that an application with an embedded or bundled Python can run on 10.m through 10.n systems, in the mean time there is a simple and safe alternative that has been used for years: build the Python on 10.m (or use a ready-built Python built on 10.m or lower).  That's what we do for the macOS Pythons provided by python.org installers, e.g. the installer variants that claim 10.9+ support are actually built on 10.9.  If you need an app bundle with an embedded Python, py2app can greatly simplify the process of constructing one.