Remove deprecated govuk-tag--inactive class

Class govuk-tag--inactive was replaced by govuk-tag--grey and deprecated
in PR #1711.

This commit removes the class completely. Users should replace any uses
of this class with `.govuk-tag--grey`.

Co-authored-by: Oliver Byford <oliver.byford@digital.cabinet-office.gov.uk>

CHANGELOG.md

@@ -57,6 +57,14 @@ If you’re calling `iff` from your own Sass, you should use [Sass's native `if`
 
 This change was introduced in [pull request #2409: Remove deprecated `iff` Sass function](https://github.com/alphagov/govuk-frontend/pull/2409).
 
+#### Remove deprecated `govuk-tag--inactive` class
+
+We've removed the `govuk-tag--inactive` class which we deprecated in [GOV.UK Frontend v3.6.0](https://github.com/alphagov/govuk-frontend/releases/tag/v3.6.0).
+
+Replace any use of this class with the `govuk-tag--grey` class.
+
+This change was introduced in [pull request #2417: Remove deprecated `govuk-tag--inactive class`](https://github.com/alphagov/govuk-frontend/pull/2417).
+
 ### Fixes
 
 We’ve made fixes to GOV.UK Frontend in the following pull requests:

src/govuk/components/tag/_index.scss

@@ -34,11 +34,6 @@
  }
  }
 
- // Deprecated. We'll remove this class in a future release. Use `.govuk-tag--grey` instead.
- .govuk-tag--inactive {
- background-color: govuk-colour("dark-grey", $legacy: "grey-1");
- }
-
  .govuk-tag--grey {
  color: govuk-shade(govuk-colour("dark-grey", $legacy: "grey-1"), 30);
  background: govuk-tint(govuk-colour("dark-grey", $legacy: "grey-1"), 90);