doc: Bump LLVM version in README

Reported-by: Ricky8955555 <[email protected]>
Signed-off-by: Bingwu Zhang <[email protected]>

Author: xtexx

README.md

@@ -47,7 +47,7 @@ Ensure you have the required dependencies:
 
  * CMake >= 3.15
  * System C/C++ Toolchain
- * LLVM, Clang, LLD development libraries == 19.x
+ * LLVM, Clang, LLD development libraries == 20.x
 
 Then it is the standard CMake build process: