fix(card): add aria-hide to card-copy (carbon-design-system#5019)

### Related Ticket(s)
carbon-design-system#4740 

### Description

Follow-up to carbon-design-system#4870 to also hide the `card-copy` text from screen readers to avoid unnecessary long description.

### Changelog

**New**

- added `aria-hidden='true'` to `card-copy` div

<!-- React and Web Component deploy previews are enabled by default. -->
<!-- To enable additional available deploy previews, apply the following -->
<!-- labels for the corresponding package: -->
<!-- *** "package: services": Services -->
<!-- *** "package: utilities": Utilities -->
<!-- *** "package: styles": Carbon Expressive -->
<!-- *** "RTL": React / Web Components (RTL) -->
<!-- *** "feature flag": React / Web Components (experimental) -->

packages/web-components/src/components/card/card.ts

@@ -78,7 +78,7 @@ class DDSCard extends StableSelectorMixin(BXLink) {
   protected _renderCopy(): TemplateResult | string | void {
     const { _hasCopy: hasCopy } = this;
     return html`
-      <div ?hidden="${!hasCopy}" class="${prefix}--card__copy">
+      <div ?hidden="${!hasCopy}" class="${prefix}--card__copy" aria-hidden="true">
         <slot @slotchange="${this._handleSlotChange}"></slot>
       </div>
     `;

packages/web-components/tests/snapshots/dds-card-cta.md

@@ -19,6 +19,7 @@
     <slot name="heading">
     </slot>
     <div
+      aria-hidden="true"
       class="bx--card__copy"
       hidden=""
     >

packages/web-components/tests/snapshots/dds-card.md

@@ -19,6 +19,7 @@
     <slot name="heading">
     </slot>
     <div
+      aria-hidden="true"
       class="bx--card__copy"
       hidden=""
     >
@@ -49,6 +50,7 @@
     <slot name="heading">
     </slot>
     <div
+      aria-hidden="true"
       class="bx--card__copy"
       hidden=""
     >

packages/web-components/tests/snapshots/dds-feature-card-block-large.md

@@ -20,6 +20,7 @@
       <slot name="heading">
       </slot>
       <div
+        aria-hidden="true"
         class="bx--card__copy"
         hidden=""
       >
@@ -58,6 +59,7 @@
         <slot name="heading">
         </slot>
         <div
+          aria-hidden="true"
           class="bx--card__copy"
           hidden=""
         >

packages/web-components/tests/snapshots/dds-feature-card.md

@@ -19,6 +19,7 @@
     <slot name="heading">
     </slot>
     <div
+      aria-hidden="true"
       class="bx--card__copy"
       hidden=""
     >
@@ -55,6 +56,7 @@
       <slot name="heading">
       </slot>
       <div
+        aria-hidden="true"
         class="bx--card__copy"
         hidden=""
       >

packages/web-components/tests/snapshots/dds-feature-cta.md

@@ -19,6 +19,7 @@
     <slot name="heading">
     </slot>
     <div
+      aria-hidden="true"
       class="bx--card__copy"
       hidden=""
     >