Merge bitcoin/bitcoin#23400: doc: fix XOnlyPubKey::IsFullyValid comment reference

037c9ee fix `XOnlyPubKey::IsFullyValid` comment reference (Sebastian Falbesoner)

Pull request description:

  The method name `CreatePayToContract` doesn't exist, very likely it was a (local) working title that was renamed to `CreateTapTweak` later.

ACKs for top commit:
  michaelfolkson:
    ACK 037c9ee
  sipa:
    ACK 037c9ee

Tree-SHA512: ab2b6ca93b66aba83c725b62f39e9f9316f3bea6f75ef35f66a2ac18b22a0a69ff2069cadab0365b28b0af2d30ad5ee3d3022194ac2024a1cdbb81d106fca0bb

Author: MarcoFalke

src/pubkey.h

@@ -230,8 +230,8 @@ class XOnlyPubKey
     XOnlyPubKey& operator=(const XOnlyPubKey&) = default;
 
     /** Determine if this pubkey is fully valid. This is true for approximately 50% of all
-     *  possible 32-byte arrays. If false, VerifySchnorr and CreatePayToContract will always
-     *  fail. */
+     *  possible 32-byte arrays. If false, VerifySchnorr, CheckTapTweak and CreateTapTweak
+     *  will always fail. */
     bool IsFullyValid() const;
 
     /** Test whether this is the 0 key (the result of default construction). This implies