Bump crossbeam-channel from 0.3.8 to 0.3.9 in /rust

[dependabot-preview]

Bumps crossbeam-channel from 0.3.8 to 0.3.9.

Changelog

Sourced from crossbeam-channel's changelog.

Version 0.7.2

• Bump crossbeam-channel to 0.3.9.
• Bump crossbeam-epoch to 0.7.2.
• Bump crossbeam-utils to 0.6.6.

Version 0.7.1

• Bump crossbeam-utils to 0.6.5.

Version 0.7.0

• Remove ArcCell, MsQueue, and TreiberStack.
• Change the interface of ShardedLock to match RwLock.
• Add SegQueue::len().
• Rename SegQueue::try_pop() to SegQueue::pop().
• Change the return type of SegQueue::pop() to Result.
• Introduce ArrayQueue.
• Update dependencies.

Version 0.6.0

• Update dependencies.

Version 0.5.0

• Update crossbeam-channel to 0.3.
• Update crossbeam-utils to 0.6.
• Add AtomicCell, SharedLock, and WaitGroup.

Version 0.4.1

• Fix a double-free bug in MsQueue and SegQueue.

Version 0.4

• Switch to the new implementation of epoch-based reclamation in
  crossbeam-epoch, fixing numerous bugs in the
  old implementation. Its API is changed in a backward-incompatible way.
• Switch to the new implementation of CachePadded and scoped thread in
  crossbeam-utils. The scoped thread API is
  changed in a backward-incompatible way.
• Switch to the new implementation of Chase-Lev deque in
  crossbeam-deque. Its API is changed in a
  backward-incompatible way.
• Export channel implemented in
  crossbeam-channel.
• Remove AtomicOption.
• Implement Default and From traits.

... (truncated)

Commits

• 29dac3c Bump crossbeam-channel to 0.3.9
• 27c94a1 Bump crossbeam-epoch to 0.7.2
• 9f50786 Bump crossbeam-utils to 0.6.6
• 4eaf9e4 Deprecate AtomicCell::get_mut
• 4bf8700 Merge pull request #396 from Marwes/unwind_safe
• 0aab8d3 Merge #403
• 109bc59 Fix meta variable misuse
• 9898f92 Merge #402
• 7169d4f update memoffset to 0.5, which contains plenty of soundness fixes
• 244a938 Merge #377
• Additional commits viewable in compare view

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[dependabot-preview]

Superseded by #175.