chore(docs): removed duplicate size class from select (#4867)

Author: schaertim

.changeset/hot-experts-wink.md

@@ -0,0 +1,5 @@
+---
+'@swisspost/design-system-documentation': patch
+---
+
+Removed duplicate size class from `select` elements using floating labels.

packages/documentation/src/stories/components/forms/select/select.stories.ts

@@ -213,8 +213,7 @@ const Template: Story = {
     const [_, updateArgs] = useArgs();
     const classes = [
       'form-select',
-      args.size,
-      args.sizeFloatingLabel,
+      args.floatingLabel ? args.sizeFloatingLabel : args.size, // Only include the appropriate size based on mode
       args.validation,
       args.floatingLabelPlaceholder && !args.value ? 'form-select-empty' : null,
     ]