The ornamental design for a stackableroutingclip, as shown and described.
FIG. 1 is a bottom side perspective view of a stackable routing clip;
FIG. 2 is a top side perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a rear side inverted view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a first side view thereof;
FIG. 8 is a second side view thereof; and,
FIG. 9 is a front side view of two stackable routing clips stacked together.
The broken lines in the drawings are included for the purpose of illustrating environmental subject matter and form no part of the claimed design. The boundary lines represent the boundary of the claim.