Clear duplicated class border-0 (#32925)

* Clear duplicated class `border-0`

* Update migration.md

Co-authored-by: Mark Otto <otto@github.com>

scss/_variables.scss

@@ -360,7 +360,6 @@ $container-padding-x: $grid-gutter-width / 2 !default;
 // scss-docs-start border-variables
 $border-width:                1px !default;
 $border-widths: (
-  0: 0,
   1: 1px,
   2: 2px,
   3: 3px,

site/content/docs/5.0/migration.md

@@ -7,11 +7,15 @@ aliases: "/migration/"
 toc: true
 ---
 
+## v5.0.0-beta3
+
+### Utilities
+
+- Dropped the `0` entry in `$border-widths` map to remove the duplicated `.border-0` class.
+
 ## v5.0.0-beta2
 
-### Sass
-
-#### Utilities
+### Utilities
 
 - Renamed `--aspect-ratio` to `--bs-aspect-ratio` to be consistent with other custom properties.
 - Extended the `.visually-hidden-focusable` helper to also work on containers, using `:focus-within`.