Update to rayon 1.4.0 (bp #11898)

[mergify]

This is an automated backport of pull request #11898 done by Mergify

Cherry-pick of c4253dc has failed:

On branch mergify/bp/v1.2/pr-11898
Your branch is up to date with 'origin/v1.2'.

You are currently cherry-picking commit c4253dc0f.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:

	modified:   Cargo.lock
	modified:   programs/bpf/Cargo.lock

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)

	both modified:   accounts-bench/Cargo.toml
	both modified:   banking-bench/Cargo.toml
	both modified:   bench-exchange/Cargo.toml
	both modified:   bench-tps/Cargo.toml
	both modified:   client/Cargo.toml
	both modified:   core/Cargo.toml
	both modified:   dos/Cargo.toml
	both modified:   ledger/Cargo.toml
	both modified:   perf/Cargo.toml
	deleted by us:   poh-bench/Cargo.toml
	both modified:   runtime/Cargo.toml

To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

Mergify commands and options

More conditions and actions can be found in the documentation.

You can also trigger Mergify actions by commenting on this pull request:

• @Mergifyio refresh will re-evaluate the rules
• @Mergifyio rebase will rebase this PR on its base branch
• @Mergifyio update will merge the base branch into this PR
• @Mergifyio backport <destination> will backport this PR on <destination> branch

Additionally, on Mergify dashboard you can:

• look at your merge queues
• generate the Mergify configuration with the simulator.

Finally, you can contact us on https://mergify.io/

[mergify]

automerge label removed due to a CI failure