[dashmap] Unsoundness in `dashmap` references

Reference returned by some methods of Ref (and similar types) may outlive the Ref and escape the lock.
This causes undefined behavior and may result in a segfault.

More information in dashmap#167 issue.

References

• https://github.com/xacrimon/dashmap/issues/167
• https://rustsec.org/advisories/RUSTSEC-2022-0002.html
• https://github.com/advisories/GHSA-mpg5-fvwp-42m2