Use multiprocessing in the fuzzer test script
Use multiprocessing in the fuzzer test script

Improved performance from ~48 seconds to ~10 seconds on my machine.

Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan,webmaster128/botan,Rohde-Schwarz-Cybersecurity/botan,Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,randombit/botan,randombit/botan,randombit/botan,Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,randombit/botan