Bump the rust-dependencies group with 3 updates (#3881)

Bumps the rust-dependencies group with 3 updates: [syn](https://github.com/dtolnay/syn), [proc-macro2](https://github.com/dtolnay/proc-macro2) and [bytemuck](https://github.com/Lokathor/bytemuck).


Updates `syn` from 2.0.66 to 2.0.68
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](dtolnay/syn@2.0.66...2.0.68)

Updates `proc-macro2` from 1.0.85 to 1.0.86
- [Release notes](https://github.com/dtolnay/proc-macro2/releases)
- [Commits](dtolnay/proc-macro2@1.0.85...1.0.86)

Updates `bytemuck` from 1.16.0 to 1.16.1
- [Changelog](https://github.com/Lokathor/bytemuck/blob/main/changelog.md)
- [Commits](Lokathor/bytemuck@v1.16.0...v1.16.1)

---
updated-dependencies:
- dependency-name: syn
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: rust-dependencies
- dependency-name: proc-macro2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: rust-dependencies
- dependency-name: bytemuck
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: rust-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.toml

@@ -94,7 +94,7 @@ isahc = "1.7.2"
 rustyline = { version = "14.0.0", default-features = false }
 dhat = "0.3.3"
 quote = "1.0.36"
-syn = { version = "2.0.66", default-features = false }
+syn = { version = "2.0.68", default-features = false }
 proc-macro2 = "1.0"
 synstructure = "0.13"
 measureme = "11.0.1"
@@ -109,7 +109,7 @@ dashmap = "5.5.3"
 num_enum = "0.7.2"
 itertools = { version = "0.13.0", default-features = false }
 portable-atomic = "1.6.0"
-bytemuck = { version = "1.15.0", default-features = false }
+bytemuck = { version = "1.16.1", default-features = false }
 arrayvec = "0.7.4"
 intrusive-collections = "0.9.6"
 cfg-if = "1.0.0"