fix(accordion): use disabled color for header description (#1236)

## PR Checklist

Please check if your PR fulfills the following requirements:

- [ ] Tests for the changes have been added (for bug fixes / features)
- [ ] Docs have been added / updated (for bug fixes / features)
- [ ] If applicable, have a visual design approval

## PR Type

What kind of change does this PR introduce?

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- [x] Bugfix
- [ ] Feature
- [ ] Code style update (formatting, local variables)
- [ ] Refactoring (no functional changes, no api changes)
- [ ] Build related changes
- [ ] CI related changes
- [ ] Documentation content changes
- [ ] Other... Please describe:

## What is the current behavior?

<!-- Please describe the current behavior that you are modifying, or
link to a relevant issue. -->

Issue Number: CDE-1658

## What is the new behavior?

## Does this PR introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this PR contains a breaking change, please describe the impact
and migration path for existing applications below. -->

## Other information

Figma spec is not yet updated to have a definition for this color, but
we have the online chat confirmation by the design team that this is a
required change

projects/angular/src/accordion/_accordion.clarity.scss

@@ -94,7 +94,8 @@
       cursor: not-allowed;
 
       .clr-accordion-status,
-      .clr-accordion-title {
+      .clr-accordion-title,
+      .clr-accordion-description {
         color: accordion-variables.$clr-accordion-panel-disabled-color;
       }
     }