My Store: added missing divider line above "View All store analytics" button in Top performers card

[pmusolino]

Closes: #14042

Description

The top performers card was shown without a divider line above the "View all store analytics" button. In comparison, the "Performance" card above it does have the line, as do the other cards. Added the missing separator.

Steps to reproduce

The separator should appear on top of "View All store analytics" button in Top performers card.

Testing information

Tested that the separator now appear on top of "View All store analytics" button in Top performers card on iOS 18 simulator, Xcode 16.

Screenshots

Before	After

---

• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Reviewer (or Author, in the case of optional code reviews):

Please make sure these conditions are met before approving the PR, or request changes if the PR needs improvement:

• The PR is small and has a clear, single focus, or a valid explanation is provided in the description. If needed, please request to split it into smaller PRs.
• Ensure Adequate Unit Test Coverage: The changes are reasonably covered by unit tests or an explanation is provided in the PR description.
• Manual Testing: The author listed all the tests they ran, including smoke tests when needed (e.g., for refactorings). The reviewer confirmed that the PR works as expected on all devices (phone/tablet) and no regressions are added.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 20.8. This milestone is due in less than 2 days. Please make sure to get it merged by then or assign it to a milestone with a later deadline.

Generated by 🚫 Danger

[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce iOS by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce iOS
	Build Number	pr14104-bf1eb76
	Version	20.6
	Bundle ID	com.automattic.alpha.woocommerce
	Commit	bf1eb76
	App Center Build	WooCommerce - Prototype Builds #11108

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[hafizrahman]

LGTM, tested in both iPad and iOS 17.5 in Simulator.

[wpmobilebot]

Version 20.7 has now entered code-freeze, so the milestone of this PR has been updated to 20.8.