fix(deps): specify Swift package versions

[nekomeowww]

Close #35

Borrowed from #39, thanks for the correct version @wytalfred provided.

Context

The following error occurs:

• apple/ml-fastvlm/app/FastVLM/FastVLM.swift:219:36 Cannot convert value of type 'MLXFast.ScaledDotProductAttentionMaskMode' to expected argument type 'MLXArray'

    public func callAsFunction(
            _ inputs: MLXArray?, cache: [KVCache]? = nil, inputEmbedding: MLXArray? = nil
        ) -> MLXArray {
            for (i, layer) in layers.enumerated() {
                h = layer(h, mask: mask, cache: cache?[i]) // <--
            }
        }

apple/ml-fastvlm/app/FastVLM/FastVLM.swift:364:31 Value of type 'UserInput.Prompt' has no member 'asMessages':

    public func prepare(prompt: UserInput.Prompt, imageTHW: THW?) -> String {
        var messages = prompt.asMessages() // <--
    }

apple/ml-fastvlm/app/FastVLM/FastVLM.swift:414:74 Extra argument 'imageGridThw' in call:

    public func prepare(input: UserInput) throws -> LMInput {
        let prompt = prepare(prompt: input.prompt, imageTHW: thw) // <--
    }

apple/ml-fastvlm/app/FastVLM/FastVLM.swift:540:36 Value of type 'LMInput.ProcessedImage' has no member 'imageGridThw':

    public func prepare(_ input: LMInput, cache: [any KVCache], windowSize: Int?) throws
        -> PrepareResult
    {
        let gridThw = input.image?.imageGridThw // <--
    }