fix(toc): address horizontal overflow (#12171)

### Related Ticket(s)

[ADCMS-7288](https://jsw.ibm.com/browse/ADCMS-7288)

### Description

Addresses horizontal scroll in the TOC.

### Changelog

**Changed**

- Adjustment to fix overflow issue with the horizontal TOC.

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packages/styles/scss/components/tableofcontents/_table-of-contents.scss

@@ -340,7 +340,7 @@ $hover-transition-timing: 95ms;
 
   .#{$prefix}--toc__navbar-chevron-right-container {
     z-index: 2;
-    inset-inline-end: -$spacing-01;
+    inset-inline-end: 0;
 
     @include breakpoint(md) {
       inset-inline-end: -$spacing-05;
@@ -417,11 +417,11 @@ $hover-transition-timing: 95ms;
       border-block-start: 1px solid $border-subtle-00;
       content: '';
       inset-block-start: -1px;
-      inset-inline: calc(-50vw + 50%) 100%;
+      inset-inline: calc(-50vw + 50% + $spacing-03) 100%;
     }
 
     &::after {
-      inset-inline: 100% calc(-50vw + 50%);
+      inset-inline: 100% calc(-50vw + 50% + $spacing-03);
     }
   }