fix: add missing aura progress bar variants (#9575)

## Description

Adds unprefixed `ERROR` and `SUCCESS` variants as those are supported by
both Lumo and Aura.

Closes #9419

## Type of change

- Bugfix

Author: sissbruecker

vaadin-progress-bar-flow-parent/vaadin-progress-bar-flow/src/main/java/com/vaadin/flow/component/progressbar/ProgressBarVariant.java

@@ -21,7 +21,11 @@
  * Set of theme variants applicable for {@code vaadin-progress-bar} component.
  */
 public enum ProgressBarVariant implements ThemeVariant {
-    LUMO_CONTRAST("contrast"), LUMO_ERROR("error"), LUMO_SUCCESS("success");
+    LUMO_CONTRAST("contrast"),
+    LUMO_ERROR("error"),
+    LUMO_SUCCESS("success"),
+    ERROR("error"),
+    SUCCESS("success");
 
     private final String variant;