Why do you want to do that anyway?

Unless you are setting up multisig or some sort of more advanced type of wallet, it's not cost effective.

When paying from a segwit address with a single private key behind it, the size of your signature in bytes will be smaller so your total cost to make a transaction will be lower.

When you pay from a taproot address with many keys or some advanced spending conditions, then a taproot signature is smaller than the equivalent on segwit, but not for a standard single signature address.

Another benefit for using a taproot address is that if you are using multisig or something advanced, no one will know if you did that or what the spending conditions were in most cases making it more private than segwit for those things.

Legacy bitcoin addresses, although the absolute least cost effective, are still supported on bitcoin, you don't need to worry about segwit becoming unsupported in the future because removing support for an old feature is a breaking change, requiring a hard fork and I don't think anyone dares to even attempt that, especially not for this reason.