feat(card): overflow hidden on cover photo for swc implementation (#2661)

Adds overflow hidden to the .spectrum-Card-coverPhoto class, to help
resolve an issue in the SWC implementation that uses sp-asset.

In SWC the photo could appear from behind the corners of the card. For
example, when increasing the corner rounding when setting the mod
--mod-card-corner-radius. This issue is not visible in Spectrum CSS.

Author: jawinn

components/card/index.css

@@ -365,6 +365,7 @@ governing permissions and limitations under the License.
 		var(--spectrum-card-preview-minimum-height)
 	);
 	box-sizing: border-box;
+	overflow: hidden;
 
 	display: flex;
 	align-items: center;