mypy

b6b66246 - tests: skip-path-normalization should be a testcase option (#15660)

tests: skip-path-normalization should be a testcase option (#15660) The "Skip path normalization" option applies to all [out]s of a test case, so it's more correct for it to be a "case" option rather than an "out" option. This also simplifies the parsing of "out" sections' args.