This package contains an exact copy of the MuSig2 code as found in
github.com/btcsuite/btcec/v2/schnorr/musig2 at the tag btcec/v2.2.2.
This corresponds to the MuSig2 BIP specification version of
v0.4.0.
We only keep this code here to allow implementing a backward compatible, versioned MuSig2 RPC.