Here's how you can ignore changes to the dreaded macOS .DS_Store files across all repositories by adding the ignore pattern to the global Git ignore file.

First, find where the global Git ignore file lives:

git config --get core.excludesfile

I found this on Stack Overflow: https://stackoverflow.com/a/22885996/2715716 It is not the top answer.

At first, this path is unset. At the provided link I found a mention that a typical path for this file is at ~/.config/git/ignore.

To set this global ignore file path, this command is used:

git config --global core.excludesfile ~/.config/git/ignore

Simply append .DS_Store to this file and re-run the respective Git CLI command or refresh the VS Code source control pane.