### Bug
The active tab bottom border appeared slightly above the TabList's light
bottom border.
### Investigation
- Initial fix: Adjusted margin-bottom to -1px in Tab component to align
borders
- This fix caused active bottom borders to disappear in tabs wrapped
with ShowPageSubContainerTabListContainer
- Found that ShowPageSubContainerTabListContainer was adding a redundant
bottom border that overlapped with TabList's border
### Solution
- Removed ShowPageSubContainerTabListContainer to eliminate the
redundant border
- Kept the -1px margin-bottom fix in Tab component
- This ensures consistent border behavior across all TabList
implementations
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