How do I make this Pantone Popup go away

You can drag the old Pantone acb files from a previous version of Photoshop (perhaps from one of your co-workers) into the Photoshop 2024 > Presets > Color Books. If that's what the files you are getting have, it will be enough to suppress the pop-up.

Checked it on an old psd with a coated Pantone swatch and it does work. Can't garantee that if the swatches are from Pantone Connect.

I'm welcome to all ideas! (:

By @Medienazubi126997956bb0y

The following script can be used to open a file while ignoring dialogs (rather than using the standard open command):

#target photoshop
var savedDisplayDialogs = app.displayDialogs;
app.displayDialogs = DialogModes.NO;
var fileOrFiles = File.openDialog("Select the file/s to open (ignoring warnings):", Multiselect = true);
for (var i = 0; i < fileOrFiles.length; i++) {
    var openFiles = app.open(File(fileOrFiles[i]));
}
app.displayDialogs = savedDisplayDialogs;

Once installed, the script could have a custom keyboard shortcut applied via Edit > Keyboard Shortcuts. You could replace the standard CMD/CTRL + O shortcut by assigning it to the installed script.

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

It's not possible to turn it off.

To use Pantone colors in your documents, you will need to download and install the Pantone Connect plug-in:

• https://www.pantone.com/eu/de/products/digital/pantone-connect-for-adobe-creative-cloud

You will also need a Pantone Connect subscription. Please refer to Pantone's Pantone Connect X Adobe FAQ for additional information.