Ensure that each editor theme is only created once (#17095)

GitOrigin-RevId: 3551e02fab44fae7fcab5cb12886d45969e3990f

services/web/frontend/js/features/source-editor/extensions/annotations.ts

@@ -24,16 +24,18 @@ export const annotations = () => [
   lintGutter({
     hoverTime: 0,
   }),
-  /**
-   * A theme which moves the lint gutter outside the line numbers.
-   */
-  EditorView.baseTheme({
-    '.cm-gutter-lint': {
-      order: -1,
-    },
-  }),
+  annotationsTheme,
 ]
 
+/**
+ * A theme which moves the lint gutter outside the line numbers.
+ */
+const annotationsTheme = EditorView.baseTheme({
+  '.cm-gutter-lint': {
+    order: -1,
+  },
+})
+
 export const lintSourceConfig = {
   delay: 100,
   // Show highlights only for errors