Merge #2676: Improve deprecation notice

33ebbac Improve deprecation notice (Tobin C. Harding)

Pull request description:

  The deprecation notice for `is_provably_unspendable` contains "is not very useful" which is a bit presumptuous to tell to users, it may very well be useful to them. Use the more helpful text that already exists in rustdoc on the function.

  Function was deprecated in #2294

ACKs for top commit:
  apoelstra:
    ACK 33ebbac I am fine with the existing text
  sanket1729:
    utACK 33ebbac

Tree-SHA512: 0611b9c414a5b01d453145d645dbfe6ef0be4000a7133bc79211c0494741638fcc19f97d6503546813f426cbc492816daf708045a76e7d67e5bd975ad8f56d5f

bitcoin/src/blockdata/script/borrowed.rs

@@ -359,7 +359,7 @@ impl Script {
     /// removed. Use `is_op_return` if you want `OP_RETURN` semantics.
     #[deprecated(
         since = "0.32.0",
-        note = "The method is not very useful, you might want `is_op_return`"
+        note = "The method has potentially confusing semantics and is going to be removed, you might want `is_op_return`"
     )]
     #[inline]
     pub fn is_provably_unspendable(&self) -> bool {