Tests/RunCMake/Swift: Update for ninja post-1.12 development

Upstream ninja commit `8e6c741a4b` ("explain" debug prints just before
each command is run, 2022-01-06) changed the `ninja -d explain` output
for our test case.  The `IncrementalSwift-second` case primarily needs
to match stdout, so update our stderr expectation to work for either
form of ninja's output.
1 file changed