Bump MACOSX_DEPLOYMENT_TARGET to 10.15 (#1773)

Hopefully will fix nightly builds

Co-authored-by: Nikita Shulga <[email protected]>

Author: atalman

wheel/build_wheel.sh

@@ -125,7 +125,7 @@ popd
 
 export TH_BINARY_BUILD=1
 export INSTALL_TEST=0 # dont install test binaries into site-packages
-export MACOSX_DEPLOYMENT_TARGET=10.13
+export MACOSX_DEPLOYMENT_TARGET=10.15
 export CMAKE_PREFIX_PATH=${CONDA_PREFIX:-"$(dirname $(which conda))/../"}
 
 SETUPTOOLS_PINNED_VERSION="=46.0.0"