Remove LLVM 20 limitation, LLVM 21 current default on many platforms

[MathewBensonCode]

There is a limitation in the repoConfiguration.json file limiting the Version of LLVM to version 20. This is due to breaking changes when formatting with clang-format.

The current version on many platforms is now LLVM 21 so trying to build on these systems using the Build Scripts fails due to this requirement.

The issue arises due to the operator bool() function in two files in particular CoroutineScheduler.h and VulkanDevice.h which looks like an identifier to the current custom clang-format rules.