--singleproc flag not respected on machines with more than 16GB of memory

Problem Description

As noted in this code (thanks to @ryfow for the investigation), if a computer has more than 16GB of memory and the --singleproc flag is passed, we will not respect the --singleproc flag because of the OR check.

// Building projects in parallel increases compiler memory usage and
// doesn't lead to dramatic performance gains (See #4739). Only enable
// parallel builds on machines with >16GB of memory to avoid OOM errors
const highMemory = totalmem() > 16 * 1024 * 1024 * 1024;
const enableParallelBuilds = singleproc === false || highMemory;

Steps To Reproduce

1. Make sure you're on a computer with more than 16GB of memory.
2. Run the following commands in the directory of your choice:

npx react-native init test
cd test
npx react-native-windows-init
yarn windows --singleproc --logging

3. Note that the argument /maxCpuCount is logged when we log the arguments passed to MSBuild.

Expected Results

I expect that /maxCpuCount is not passed to MSBuild when the --singleproc flag is passed.

CLI version

11.3.7

Environment

System:
  OS: Windows 10 10.0.19045
  CPU: (16) x64 11th Gen Intel(R) Core(TM) i7-11850H @ 2.50GHz
  Memory: 19.97 GB / 31.73 GB
Binaries:
  Node:
    version: 18.18.0
    path: C:\Program Files\nodejs\node.EXE
  Yarn:
    version: 1.22.19
    path: ~\AppData\Roaming\npm\yarn.CMD
  npm:
    version: 9.8.1
    path: C:\Program Files\nodejs\npm.CMD
  Watchman: Not Found
SDKs:
  Android SDK: Not Found
  Windows SDK:
    AllowDevelopmentWithoutDevLicense: Enabled
    AllowAllTrustedApps: Enabled
    Versions:
      - 10.0.19041.0
      - 10.0.22621.0
IDEs:
  Android Studio: Not Found
  Visual Studio:
    - 17.7.34031.279 (Visual Studio Professional 2022)
Languages:
  Java: Not Found
  Ruby: Not Found
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 18.2.0
    wanted: 18.2.0
  react-native:
    installed: 0.72.5
    wanted: 0.72.5
  react-native-windows:
    installed: 0.72.9
    wanted: 0.72.9
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: false
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Target Platform Version

10.0.19041

Target Device(s)

Desktop

Visual Studio Version

Visual Studio 2022

Build Configuration

Debug

Snack, code example, screenshot, or link to a repository

No response

Inspect packages/@react-native-windows/cli/src/utils/msbuildtools.ts around the highMemory and MSBuild argument logic at the referenced lines. Reproduce the yarn windows --singleproc --logging command on a machine with more than 16GB of memory, then verify that /maxCpuCount is absent when the flag is used.