Bump crossbeam-channel from 0.5.14 to 0.5.15

Bumps [crossbeam-channel](https://github.com/crossbeam-rs/crossbeam) from 0.5.14 to 0.5.15.
- [Release notes](https://github.com/crossbeam-rs/crossbeam/releases)
- [Changelog](https://github.com/crossbeam-rs/crossbeam/blob/master/CHANGELOG.md)
- [Commits](crossbeam-rs/crossbeam@crossbeam-channel-0.5.14...crossbeam-channel-0.5.15)

---
updated-dependencies:
- dependency-name: crossbeam-channel
  dependency-version: 0.5.15
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/tools/miri/Cargo.lock

@@ -257,9 +257,9 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-channel"
-version = "0.5.14"
+version = "0.5.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "06ba6d68e24814cb8de6bb986db8222d3a027d15872cabc0d18817bc3c0e4471"
+checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
 dependencies = [
  "crossbeam-utils",
 ]