tweak(ui): styling for image collection fields

Author: psychedelicious

invokeai/frontend/web/src/features/nodes/components/flow/nodes/Invocation/fields/inputs/ImageFieldCollectionInputComponent.tsx

@@ -82,14 +82,7 @@ export const ImageFieldCollectionInputComponent = memo(
         justifyContent="center"
       >
         {(!field.value || field.value.length === 0) && (
-          <UploadMultipleImageButton
-            w="full"
-            h="auto"
-            isError={isInvalid}
-            onUpload={onUpload}
-            fontSize={24}
-            variant="ghost"
-          />
+          <UploadMultipleImageButton w="full" h="auto" isError={isInvalid} onUpload={onUpload} fontSize={24} />
         )}
         {field.value && field.value.length > 0 && (
           <Box w="full" h="auto" p={1} sx={sx} data-error={isInvalid} borderRadius="base">