Fix select width issue on firefox

[lorgan3]

Description

This fixes an issue that on firefox the select grows larger than allowed when a long option is selected

Testing setup in case you want to check this for yourself:
Select basic story:

export const basic: ComponentStory<typeof Select> = (args) => (
  <Flex>
    <Box flex={1}>
      <Select {...args} />
    </Box>
    <Box flex={1} />
  </Flex>
);

Screenshot before this PR

Screen.Recording.2023-08-22.at.09.10.36.mov

Screenshot after this PR

Screen.Recording.2023-08-22.at.09.10.57.mov

Breaking changes

N/a

[KristofColpaert]

Looks great 👍