**What type of PR is this?**
Bug fix
**What does this PR do? Why is it needed?**
It appears that #16216 introduced hashtree integration but broke builds
on macOS Intel (darwin_amd64).
```
Error:
Undefined symbols for architecture x86_64:
"_github.com/OffchainLabs/hashtree.HashtreeHash"
```
The Bazel patch for hashtree was missing `wrapper_darwin_amd64.s`. So,
`//go:noescape` in `bindings.go` assumes that symbols are available
elsewhere, and while on other platforms optimized version is used, on
Darwin we have stub (symbol still must be available), which needs to be
referenced -- hence, this PR.
**Other notes for review**
I've re-checked using `bazel clean && bazel build //cmd/beacon-chain` --
it was failing before, works now.
cc @potuz as original patch author
**Acknowledgements**
- [x] I have read
[CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
- [x] I have included a uniquely named [changelog fragment
file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
- [x] I have added a description with sufficient context for reviewers
to understand this PR.
- [x] I have tested that my changes work as expected and I added a
testing plan to the PR description (if applicable).
Co-authored-by: Potuz <potuz@prysmaticlabs.com>
This PR fixes release builds that fail because of hashtree's patch.
Should be in conjunction with #16281
---------
Co-authored-by: Preston Van Loon <preston@pvl.dev>