[Product Variation Attributes] Do not use ignore case when renaming attributes

[toupper]

Closes: #12561

Description

With this PR we fix the issue that was preventing users from renaming their variation attributes from a different case (upper to lower or vice-versa)

Note: there are other cases where we ignore the case for attributes: when adding a new attribute, or when deleting them. I preferred to leave them like that as we could have unexpected cases if we modified. For renaming it's ok though, as this case is isolated enough.

Steps to reproduce

1. Attempt to rename a product attribute by just changing any number of characters from lower case to upper case.
2. Then navigate back
3. See a toast stating that the product attribute
4. The product attribute won't be renamed and you'll have to remove it and add it again with the correct letter case. See screen recording for extra details.

Testing information

See steps to reproduce

The tests that have been performed

I ensured with the steps to reproduce that it's working properly. I also verified it in wc-admin

Images/gif

Before

CannotRename.mp4

After

Screen_Recording_20240913_160949_WooCommerce.Dev.mp4

• I have considered if this change warrants release notes and have added them to RELEASE-NOTES.txt if necessary. Use the "[Internal]" label for non-user-facing changes.

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 big (tablet) and small (phone) in case of UI changes, and no regressions are added.

[wpmobilebot]

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

	App Name	WooCommerce-Wear Android
	Platform	⌚️ Wear OS
	Flavor	Jalapeno
	Build Type	Debug
	Commit	baa7dea
	Direct Download	woocommerce-wear-prototype-build-pr12608-baa7dea.apk

[wpmobilebot]

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

	App Name	WooCommerce Android
	Platform	📱 Mobile
	Flavor	Jalapeno
	Build Type	Debug
	Commit	baa7dea
	Direct Download	woocommerce-prototype-build-pr12608-baa7dea.apk

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 40.63%. Comparing base (d1eb9ed) to head (baa7dea).
Report is 6 commits behind head on trunk.

Files with missing lines	Patch %	Lines
...roid/ui/products/details/ProductDetailViewModel.kt	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk   #12608      +/-   ##
============================================
+ Coverage     40.61%   40.63%   +0.02%     
- Complexity     5685     5687       +2     
============================================
  Files          1230     1230              
  Lines         69167    69167              
  Branches       9575     9575              
============================================
+ Hits          28093    28109      +16     
+ Misses        38493    38474      -19     
- Partials       2581     2584       +3     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.