CMake Dependency needs updating due to use of VS 2022 Generator

[capnkenny]

Describe the issue:
When attempting to build NovelRT on Windows 10 or 11 with Visual Studio 2022 installed, CMake versions 3.19 and 3.20 will fail using the default settings with the following error: "CMake Error: Could not create named generator Visual Studio 17 2022"
This appears to occur when using Visual Studio Code, however it can happen with other IDEs if not using Ninja or Unix Makefiles by default.

Please provide the steps to reproduce if possible:

1. Clone the repo
2. Open Visual Studio Code (configured with CMake Tools / C++ Support enabled)
3. Run the default configure command
4. See error

Expected behaviour:
The CMake version dependency should be updated to 3.21 in readme, Wiki, and the root CMakeLists.txt.

Please tell us about your environment:

• OS Version: Windows 11 22H2
  If building from source:
• Compiler Version: Visual Studio 2022 v17.4.3
• IDE: Visual Studio Code, C/C++ (Microsoft) extension installed
• Git fork/branch URL: N/A, using main branch

Additional context:
It seems to be failing at the command level, before the CMakeLists.txt file is even processed.

[RubyNova]

I'll deal with this.

[capnkenny]

Possibly out of date - currently, CI is using CMake 3.24 and our CMakeLists will throw a fatal error if it's not at least that, so we should probably update accordingly.