Change getUid return type from number to string

src/ol/style/Fill.js

@@ -81,7 +81,7 @@ class Fill {
         if (Array.isArray(color) || typeof color == 'string') {
           this.checksum_ = 'f' + asString(/** @type {import("../Color.js").Color|string} */ (color));
         } else {
-          this.checksum_ = getUid(this.color_).toString();
+          this.checksum_ = getUid(this.color_);
         }
       } else {
         this.checksum_ = 'f-';

src/ol/style/Icon.js

@@ -149,7 +149,7 @@ class Icon extends ImageStyle {
       5); // `imgSize` must be set when `image` is provided
 
     if ((src === undefined || src.length === 0) && image) {
-      src = /** @type {HTMLImageElement} */ (image).src || getUid(image).toString();
+      src = /** @type {HTMLImageElement} */ (image).src || getUid(image);
     }
     assert(src !== undefined && src.length > 0,
       6); // A defined and non-empty `src` or `image` must be provided

src/ol/style/Stroke.js

@@ -259,7 +259,7 @@ class Stroke {
         if (typeof this.color_ === 'string') {
           this.checksum_ += this.color_;
         } else {
-          this.checksum_ += getUid(this.color_).toString();
+          this.checksum_ += getUid(this.color_);
         }
       } else {
         this.checksum_ += '-';