chore(progress-bar): add deprecation warning for over-background

Author: cdransf

.changeset/easy-jobs-brush.md

@@ -0,0 +1,5 @@
+---
+'@spectrum-web-components/progress-bar': patch
+---
+
+**Added**: Deprecation warning for the over-background attribute.

packages/progress-bar/src/ProgressBar.ts

@@ -145,6 +145,15 @@ export class ProgressBar extends SizedMixin(
             }
         }
 
+        if (change.has('over-background') && window.__swc.DEBUG) {
+            window.__swc.warn(
+                this,
+                `The "over-background" attribute on <${this.localName}> has been deprecated and will be removed in a future release. Use "static-color='white'" instead.`,
+                'https://opensource.adobe.com/spectrum-web-components/components/progress-bar/#variants',
+                { level: 'deprecation' }
+            );
+        }
+
         if (window.__swc.DEBUG) {
             if (
                 !this.label &&