Unfortunately its quite complicated to animate a border around a circle.
Here’s a revised codepen of an old demo of mine that shows one solution.
Most of it is smoke and mirrors
It’s quite hard to understand but the basics are that 2 circles are clipped in half and then each circle is half rotated around the circle. One half circle hides the other one until a half animation is complete and then the other half is animated to complete the circle.
There is no border as such but a solid background which is hidden by the inner elements to just allow the edge of the circles to be seen.
The SVG path is a dashed line with the length of dashes and gaps equal to the circumference. Animating the dash offset causes the circle to appear over a period of 5 seconds. There’s also a delay of 5 seconds before the animation starts.