Use Lilu 1.5.1 new APIs

[goodbest]

Lilu 1.5.1 introduces lots of methods and apis that have been adopted in this patch:

• Added lilu_os_memmem and lilu_os_memchr APIs
• Added getSharedCachePath API to obtain current cache path
• Added LIKELY/UNLIKELY macros https://github.com/acidanthera/Lilu/releases/tag/1.5.1

So I guess there's no need to maintain those implementations in this repo?