Ignore BOTAN_DEPRECATED in Doxygen config
Ignore BOTAN_DEPRECATED in Doxygen config

Fixes #1266

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