Fixed label background rendering. (#11293)

* Fixed label background rendering.

* Add IKangXu (@IKangXu) to the list of contributors and update changes.md

* Update CHANGES.md

* Fix background image for label

---------

Co-authored-by: IKangXu <xukang@emapgis.com>

Author: IKangXu

CHANGES.md

@@ -9,6 +9,7 @@
 - Fixed color creation from CSS color string with modern "space-separated" syntax. [#11271](https://github.com/CesiumGS/cesium/pull/11271)
 - Fixed a race condition when loading cut-out terrain. [#11296](https://github.com/CesiumGS/cesium/pull/11296)
 - Fixed async behavior for custom terrain and imagery providers. [#11274](https://github.com/CesiumGS/cesium/issues/11274)
+- Fixed label background rendering. [#11293](https://github.com/CesiumGS/cesium/pull/11293)
 
 ### 1.105.2 - 2023-05-15
 

CONTRIBUTORS.md

@@ -358,3 +358,4 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute to Cesiu
 - [Jason Summercamp](https://github.com/fullstacc)
 - [Shapovalov Kirill](https://github.com/ShapovalovKL)
 - [Alexander Popoff](https://github.com/aerialist7)
+- [IKangXu](https://github.com/IKangXu)

packages/engine/Source/Scene/Billboard.js

@@ -1169,13 +1169,6 @@ Billboard.prototype._loadImage = function () {
   }
 
   if (defined(image)) {
-    // No need to wait on imageIndexPromise since these have already been added to the atlas
-    const index = atlas.getImageIndex(imageId);
-    if (defined(index)) {
-      completeImageLoad(index);
-      return;
-    }
-
     imageIndexPromise = atlas.addImage(imageId, image);
   }
   if (defined(imageSubRegion)) {