lockfile: order of content changes on a repro

[skshetry]

Eg: if we change order of outs in the pipeline file, and run repro, it's smart to detect that nothing was changed. But, if the outs or deps has really changed in the workspace and the stage is run, it will generate the lockfile which generates the content in the order of contents of pipeline file. It's not big issue, but it can be annoying to look at the diff.

But, leaving it as-is for now. Will come to this as soon as big tasks are complete.