Remove box-shadow from avatar styles for a cleaner appearance (#2137)

* Remove box-shadow from avatar styles for a cleaner appearance

* Create ten-houses-punch.md

.changeset/ten-houses-punch.md

@@ -0,0 +1,5 @@
+---
+"@tabler/core": patch
+---
+
+Fix `.avatar-upload` double borders 

core/scss/ui/_avatars.scss

@@ -90,6 +90,7 @@
   height: 4rem;
   border: var(--#{$prefix}border-width) dashed var(--#{$prefix}border-color);
   background: $form-check-input-bg;
+  box-shadow: none;
   flex-direction: column;
   @include transition(color $transition-time, background-color $transition-time);