Fix CMake invocation for 3.10 compat

[stuartmorgan-g]

Description

The -S/-B format of specifying source and build directories wasn't added
until 3.13. For 3.10 compatibility, use the older form of having the
working directory as the build directory, and the last argument as the
source directory.

Related Issues

Fixes #57409

Tests

I added the following tests: None; updated existing tests to expect the older command line format.

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[stuartmorgan-g]

I really need to do an end-to-end test with 3.10 to make sure there aren't other compat issues lurking that I missed in writing it, but this fixes the immediate problem. (We also need end-to-end automated testing with an Ubuntu 18.04 image, but that's already on the TODO list.)

[jonahwilliams]

LGTM

[MrGreenTea]

Maybe adding a version check of cmake in doctor could also be helpful?

[stuartmorgan-g]

Maybe adding a version check of cmake in doctor could also be helpful?

There is already a version check.