[3.7] bpo-32726: macOS 10.6+ installer now builds Tcl/TK 8.6 (GH-6307) by ned-deily · Pull Request #6308 · python/cpython
Build and link with private copy of Tcl/Tk 8.6 for the macOS 10.6+
installer. The 10.9+ installer variant already does this. This means that
the Python 3.7 provided by the python.org macOS installers no longer need or
use any external versions of Tcl/Tk, either system-provided or user-
installed, such as ActiveTcl.