Add pseudo check

[Koeng101]

https://github.com/Koeng101/dnadesign/blob/85e882045b7cd1e61284431e5e3b8985243f1fbd/lib/synthesis/codon/codon.go#L264C1-L267C5

for _, feature := range sequence.Features {
        if feature.Type == "CDS" {
            if _, ok := feature.Attributes["pseudo"]; ok {
                continue
            }
            seq, _ := feature.GetSequence()
            codingRegionsBuilder.WriteString(seq)
            genes++
        }
    }