Merge rust-bitcoin/rust-bitcoin#5273: Add exception for resize_if_needed mutant

b7aa867 Add exception for resize_if_needed mutant (Jamil Lambert, PhD)

Pull request description:

  Mutation testing changes a `*=` to `+=` in the function that increases the buffer size when needed. The difference is purely performant and testing it adds no value.
  
  Exclude the mutant.
  
  Closes #5267


ACKs for top commit:
  apoelstra:
    ACK b7aa867; successfully ran local tests
  tcharding:
    ACK b7aa867


Tree-SHA512: 4f88157bbe52b7a1a05d8947290bfd493be7a48b93cadc8b5bbff701a0358157a525b0248ab18655d45c0adde8ddab47a3058ddd8f6d8bb49657bb8758e38160

Author: apoelstra

.cargo/mutants.toml

@@ -49,6 +49,7 @@ exclude_re = [
     "primitives/.* <impl Encoder for .*Encoder<'_>>::current_chunk", # Replacing the return with Some(vec![]) causes an infinite loop.
     "primitives/.* <impl Encoder for .*Encoder<'_>>::advance", # Replacing the return with true causes an infinite loop.
     "primitives/.* <impl Decoder for WitnessDecoder>::push_bytes", # Replacing == with != causes an infinite loop
+    "primitives/.* WitnessDecoder::resize_if_needed", # Replacing *= with += still resizes the buffer making the mutant untestable.
 
     # consensus_encoding - most of these are for mutations in the logic used to determine when to stop encoding or decoding.
     "consensus_encoding/.* <impl Decoder for ArrayDecoder<N>>::push_bytes", # Mutations cause an infinite loop