Fix activity panel not showing unread when closed

[nathanss]

Submission Review Guidelines:

• I have followed the WooCommerce Contributing Guidelines and the WordPress Coding Standards.
• I have checked to ensure there aren't other open Pull Requests for the same update/change.
• I have reviewed my code for security best practices.
• Following the above guidelines will result in quick merges and clear and detailed feedback when appropriate.

Changes proposed in this Pull Request:

Fix activity panel not showing unread when closed.

I refactored some code and removed the && isPanelOpen clause from hasAbbreviatedNotificationsFn. Please review if that's actually needed for some reason, as it's passed to InboxPanel as a prop.

Closes #38139 .

How to test the changes in this Pull Request:

Using the WooCommerce Testing Instructions Guide, include your detailed testing instructions:

1. In a fresh site with WooCommerce, hide both setup tasklist and “Things to do next” tasklist
2. Create a new order with Processing status
3. Go to a URL where "Activity" button appears (e.g. Product > Add) and toggle “Activity”, the red badge should appear with panel both open and closed.

[github-actions]

Hi @octaedro,

Apart from reviewing the code changes, please make sure to review the testing instructions as well.

You can follow this guide to find out what good testing instructions should look like:
https://github.com/woocommerce/woocommerce/wiki/Writing-high-quality-testing-instructions

[github-actions]

Test Results Summary

Commit SHA: 321710b

Test 🧪	Passed ✅	Failed 🚨	Broken 🚧	Skipped ⏭️	Unknown ❔	Total 📊	Duration ⏱️
API Tests	267	0	0	2	0	269	1m 11s
E2E Tests	188	0	0	10	0	198	20m 50s

---

To view the full API test report, click here.
To view the full E2E test report, click here.
To view all test reports, visit the WooCommerce Test Reports Dashboard.

[codecov]

Codecov Report

Merging #38173 (7cb059c) into trunk (c4c517c) will decrease coverage by 0.0%.
The diff coverage is 29.3%.

Additional details and impacted files

@@            Coverage Diff             @@
##             trunk   #38173     +/-   ##
==========================================
- Coverage     51.2%    51.2%   -0.0%     
- Complexity   17421    17439     +18     
==========================================
  Files          440      440             
  Lines        80640    80708     +68     
==========================================
+ Hits         41312    41332     +20     
- Misses       39328    39376     +48     

Impacted Files	Coverage Δ
...ocommerce/includes/abstracts/abstract-wc-order.php	76.4% <ø> (ø)
...ommerce/includes/abstracts/abstract-wc-product.php	88.3% <ø> (ø)
...ocommerce/includes/admin/class-wc-admin-addons.php	0.0% <ø> (ø)
...ocommerce/includes/admin/class-wc-admin-assets.php	0.0% <ø> (ø)
...ocommerce/includes/admin/class-wc-admin-status.php	14.5% <ø> (ø)
.../includes/admin/helper/class-wc-helper-updater.php	28.9% <ø> (ø)
...udes/admin/settings/class-wc-settings-products.php	98.6% <ø> (ø)
...lugins/woocommerce/includes/class-wc-countries.php	95.4% <ø> (ø)
plugins/woocommerce/includes/class-wc-coupon.php	73.9% <ø> (ø)
...woocommerce/includes/class-wc-frontend-scripts.php	0.0% <ø> (ø)
... and 14 more

... and 2 files with indirect coverage changes

[octaedro]

Good job @nathanss! LGTM 🚀