fix(progress-indicator): label attribute not showing when there is wh…

…en there is white space before closing tag (#11430)

…ite space before closing

### Related Ticket(s)

Closes #11167

### Description

The label text of the web component does not show when there are spaces or line breaks before the closing tag.
There is an unnamed slot in the component, which replaces the `<p>` tag with the white space inside the component.

### Changelog

**Changed**

- Named the slot the to `label-text`.

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packages/carbon-web-components/src/components/progress-indicator/progress-step.ts

@@ -126,7 +126,7 @@ export default class CDSProgressStep extends FocusMixin(LitElement) {
           }[state],
           children: svgLabel ? svg`<title>${svgLabel}</title>` : undefined,
         })}
-        <slot>
+        <slot name="label-text">
           <p
             role="button"
             class="${prefix}--progress-label"

packages/carbon-web-components/tests/snapshots/cds-checkbox.md

@@ -51,7 +51,6 @@
 >
   <span class="cds--checkbox-label-text">
     <slot>
-      Checkbox label
     </slot>
   </span>
 </label>
@@ -61,3 +60,4 @@
 </div>
 
 ```
+

packages/carbon-web-components/tests/snapshots/cds-progress-step.md

@@ -9,7 +9,7 @@
   class="cds--progress-step-button"
   tabindex="0"
 >
-  <slot>
+  <slot name="label-text">
     <p
       aria-describedby="label-tooltip"
       class="cds--progress-label"
@@ -34,7 +34,7 @@
   class="cds--progress-step-button"
   tabindex="0"
 >
-  <slot>
+  <slot name="label-text">
     <p
       aria-describedby="label-tooltip"
       class="cds--progress-label"