docs: Update README.md for ARM64 latest version is called ARM64/ARM64EC

[ourabigdev]

PR Details

installing the latest arm build tools didn't help building the engine because is needed ARM64 build tools and ARM64 build tools have no latest version but there is one called ARM64/ARM64EC build tools and it has a latest version and after asking on discord @Eideren said that i should install it and when i installed it i had no problem building the engine

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.

[Eideren]

Thanks !