build: use `target_include_directories` (NFC)
build: use `target_include_directories` (NFC)

Use `target_include_directories` rather than `target_compile_options`
This should be entirely equivalent.  NFCI.

apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation,apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation,e78l/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation,apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation