Fix checkbox label styling on product page tabs

[mattsherman]

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:

This PR fixes the styling of checkbox labels on the product page tabs for smaller viewports (max-width: 1280px).

This is not a new bug... it has existed since at least 2.5.0 (I went back to that version and could reproduce it). To be honest, I'm not really sure why a very visible issue like this hasn't been fixed ever. Maybe I'm one of the few that regularly use a smaller viewport?

Before

After

How to test the changes in this Pull Request:

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

1. Go to Products > Add New (/wp-admin/post-new.php?post_type=product)
2. Go to the Inventory tab
3. Verify the checkboxes are displayed correctly on both larger and smaller viewports. The checkbox label should always start right next to the checkbox, never fully below it.

[github-actions]

Hi , @woocommerce/mothra-enhancements

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: a0552e0

Test 🧪	Passed ✅	Failed 🚨	Broken 🚧	Skipped ⏭️	Unknown ❔	Total 📊	Duration ⏱️
API Tests	259	0	0	2	0	261	0m 49s
E2E Tests	187	0	0	10	0	197	15m 21s

---

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 #37791 (a0552e0) into trunk (c226fa1) will decrease coverage by 0.0%.
The diff coverage is 0.0%.

Additional details and impacted files

@@            Coverage Diff             @@
##             trunk   #37791     +/-   ##
==========================================
- Coverage     51.6%    51.6%   -0.0%     
- Complexity   17260    17261      +1     
==========================================
  Files          429      429             
  Lines        79928    79942     +14     
==========================================
- Hits         41213    41211      -2     
- Misses       38715    38731     +16     

Impacted Files	Coverage Δ
...ocommerce/includes/admin/class-wc-admin-assets.php	0.0% <0.0%> (ø)
...ugins/woocommerce/includes/class-wc-post-types.php	1.1% <0.0%> (-<0.1%)	⬇️
...commerce/includes/class-wc-rest-authentication.php	3.4% <0.0%> (-<0.1%)	⬇️
plugins/woocommerce/includes/class-woocommerce.php	20.4% <ø> (ø)
...ludes/tracks/events/class-wc-products-tracking.php	0.0% <ø> (ø)
plugins/woocommerce/woocommerce.php	15.4% <ø> (ø)

... and 1 file with indirect coverage changes

[nathanss]

Thanks for the proactivity!