tl;dr Just ignore apt related "W: ... _apt ..." warning lines. They're non-fatal, and for the most part you can't fix this, and you'll get the same results with or without the warning.
tl;dr Just ignore apt related "W: ... _apt ..." warning lines. They're non-fatal, and for the most part you can't fix this, and you'll get the same results with or without the warning.