updated the `read_metrics_from_flac_by_bloc'

[joshuabvarghese]

• Converted channels to usize for better compatibility.
• Used a dynamic vector sample_channel_data to hold samples for each channel.
• Iterated over channels using channel as u32 to avoid type mismatches.
• Pushed each channel's sample to the sample_vec vector.
• Updated the debug print statement to display the sample_channel_data vector.

[rukai]

What you have is fine but for reference we can resolve the clippy lint like this:

            for (i, channel) in sample_channel_data.iter_mut().enumerate() {
                *channel = block.sample(i as u32, sample) as u16;
            }

[rukai]

We could shorten this to: sample_vec.extend(&sample_channel_data);