CVE-2023-6180: tokio-boring vulnerable to resource exhaustion via memory leak

The tokio-boring library in version 4.0.0 is affected by a memory leak issue that can lead to excessive resource consumption and potential DoS by resource exhaustion. The set_ex_data function used by the library did not deallocate memory used by pre-existing data in memory each time after completing a TLS connection causing the program to consume more resources with each new connection.