log4j versions below 2.15.0 are (under circumstances) vulnerable to remote code execution attacks, so this PR updates these to be sure Izanami can't be hacked that way (I'm not entirely sure where log4j and slf4j are used in the codebase, might be a candidate for being removed completely as well).
See https://www.lunasec.io/docs/blog/log4j-zero-day/#example-vulnerable-code
log4j versions below 2.15.0 are (under circumstances) vulnerable to remote code execution attacks, so this PR updates these to be sure Izanami can't be hacked that way (I'm not entirely sure where log4j and slf4j are used in the codebase, might be a candidate for being removed completely as well).