Well segment: Change border color to default gray-100

- https://gitlab.com/gitlab-org/gitlab/-/merge_requests/147674

Changelog: changed

app/assets/stylesheets/bootstrap_migration_components.scss

@@ -118,9 +118,9 @@ input[type='file'] {
   margin-bottom: 16px;
 
   .ref-list {
-    border-color: $well-inner-border;
+    border-color: $gray-100;
   }
-  
+
   .well-segment {
     padding: 1rem;
 
@@ -132,7 +132,7 @@ input[type='file'] {
     }
 
     &:not(:last-of-type) {
-      border-bottom: 1px solid $well-inner-border;
+      border-bottom: 1px solid $gray-100;
     }
 
     p,

app/assets/stylesheets/framework/variables.scss

@@ -122,8 +122,6 @@ $contextual-sidebar-border-color: #e9e9e9;
 $border-color: $gray-100;
 $shadow-color: $t-gray-a-08;
 $well-expand-item: #e8f2f7 !default;
-$well-inner-border: #eef0f2 !default;
-$well-light-border: #f1f1f1;
 $nav-active-bg: $t-gray-a-08;
 
 /*

app/assets/stylesheets/framework/wells.scss

@@ -8,7 +8,7 @@
     padding: $gl-padding;
 
     &:not(:last-of-type) {
-      border-bottom: 1px solid $well-inner-border;
+      border-bottom: 1px solid $gray-100;
     }
 
     &.borderless {

app/assets/stylesheets/themes/_dark.scss

@@ -43,4 +43,3 @@ $line-added-dark: $green-200;
 $line-removed-dark: $red-200;
 
 $well-expand-item: $gray-200;
-$well-inner-border: $gray-200;