I copied some notes to a new flow, and when I open the key editor in order to remove the playing techniques at the bottom, it won’t let me?
So you want the slurs visible but not audibly legato?
The Playing Techniques at the bottom of the Key Editor are for information only: they can’t be deleted or edited there.
Slurs in the notation trigger the Legato expression, as defined in your Expression Map. Even if this isn’t in your Map, Dorico makes Legato notes longer by default. You can set this in Playback Options. (Or in the Overrides of your Expression Map, if you don’t want the change to affect all instruments.)
Or you can select individual slurs and activate the Suppress playback property.