Do not generate a build parameters file if a custom one has been passed (#3693)
Do not generate a build parameters file if a custom one has been passed (#3693)

This already works, because it seems like the second `--buildParametersFile` option wins when invoking `xcbuild`, but it seems better to make this more explicit and more clean to not generate a file if the expectation is that it won't be used.
apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager