If you click on the link, this constraint file is missing. Also, there are no instructions on what to do with it. Is this constraint file required? How do I get it?
The XDC file should be added to every Vivado project.
If you are thinking of the board files, these can be added to the Vivado installation (once), and will be available for every project. PYNQ-Z2 board files are here: https://d2m32eurp10079.cloudfront.net/Download/pynq-z2.zip
(Add to Vivado install path]\Xilinx\Vivado\20XX.X\data\boards\board_files )