array_unique() for a 2d array, but based on a single column only

Question

For instance

[
    ['foo' => 1, 'bar' => 2],
    ['foo' => 1, 'bar' => 3],
    ['foo' => 2, 'bar' => 4]
]

I'd like to become

[
    ['foo' => 1, 'bar' => 2],
    ['foo' => 2, 'bar' => 4]
]

Based on the duplicate value for foo. I'm not bothered which of the entries goes, either is fine.

I can write something to loop over the array and perform this check myself, but I wondered if there's a built-in function (or combination of a couple of them) that can achieve this result?