components/LoadingSpinner.scss: pull math.div outside of calc function

Author: lemke-ethan

src/components/LoadingSpinner.scss

@@ -3,12 +3,13 @@
 @use "sass:math";
 
 $size: 30px;
+$half-size: math.div($size, 2);
 
 .spinner {
   position: relative;
   // TODO: #9: address build warnings
-  top: calc(50% - math.div(#{$size}, 2));
-  left: calc(50% - math.div(#{$size}, 2));
+  top: calc(50% - $half-size);
+  left: calc(50% - $half-size);
   width: $size;
   height: $size;
   animation: spinner 0.75s linear infinite;