Add token usage to the action outputs

[larslockefeer]

Hi there, first of all thanks for making this GitHub action wrapper for Codex available 🙏

For an integration at work, I was looking into options for retrieving the total number of tokens used by the codex execution. After coming up empty while looking into the command line options of the codex CLI, I noticed the output log already captures the total amount of tokens used.

Therefore, I figured the easiest way to achieve what I want is to capture the output to a logfile besides sending it to stdout and then parse the tokens used when the run has finished.

I'm filing this PR mostly to see if there is interest in this approach, I haven't tested my changes yet. Happy to contribute further if this is going into a desirable direction at all. Apologies if this is a waste of your time 😬

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[larslockefeer]

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[bolinfest]

I don't think this is the right place to fix this. If this is important, then there should be an optional flag to codex exec that takes a path to a file where the token info should be recorded and we should write it as JSON or some format that can be read programmatically.

[bolinfest]

Why should sudo be necessary? Also, this will not work on Windows.

[larslockefeer]

Fair point, this was the simplest workaround I could see but I agree that it may be too pragmatic (and in the current implementation also not robust enough yet). For now I won't have the ability to look into adding this capability to codex itself but maybe I'll try later, thanks 🙏

I'll close this PR because it is irrelevant then.