Remove charset attribute from link elements according to W3C recommendations

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X, 7.1.X, 7.2.X, Master
• Fix Version/s: 7.0.0 DXP FP93, 7.0.10.14 DXP SP14, 7.0.X, 7.1.10 DXP FP18, 7.1.X, 7.2.10 DXP FP7, 7.2.X, 7.3.3 CE GA4, 7.3.10 DXP GA1, Master
• Component/s: JS Themes Toolkit
• Labels:
  • ee-ts
  • liferay-dxp-70-sp14
  • liferay-fixpack-de-93-7010
  • liferay-fixpack-dxp-18-7110
  • liferay-fixpack-dxp-7-7210
• Branch Version/s:
  7.2.x, 7.1.x, 7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/wincent/liferay-portal/pull/286

Steps to Reproduce
Load css files that would be added to the DOM in a link element.
Run W3C official validation

Actual Behavior
There is no errors.

Expected Behavior
You can see the error:

Error: The charset attribute on the link element is obsolete. Use an HTTP Content-Type header on the linked resource instead.

You can see same information about using charset attribute in link elements in W3C documentation.