Often, when I open gmail.com in Safari for macOS, I get the following obtrusive pop-up ad in the corner of my email app:
Google recommends using Chrome
Easily search on Google with the fast, secure browser
Don't switch | Yes
I obviously want to keep using Safari, which is why I select Don't switch, but the annoying pop-up advertisement will be there next day or week when I open Gmail again.
How can I disable this pop-up advertisement for the Chrome browser in the gmail web interface?