Remove dead variables in make_ptc_api_call

[SNO7E-G]

Summary. Delete two local variables that were assembled but never read.

Problem. auth_header and additional_curl_params were built as quoted strings (-H "…", -F "…") but nothing consumed them — each curl call inlines its own headers and form fields. The code reads as if auth flows through a variable when it doesn't.

Change. Remove the four auth_header / additional_curl_params assignments; keep every interleaved log line (Using API token…, No API token provided…, Including additional_translation_files…) and refresh the stale comment, so output is unchanged.

Risk. None — the variables had no readers; curl behaviour is byte-identical.

Verified. grep shows zero remaining references; test-runner (12) and test-error-shapes (22, exercises the upload/process path) green. Independent review confirmed truly dead, no log lines dropped.

[pavel-te]

Merged — thank you, and sorry it sat here for two weeks.

I verified the claim independently rather than taking it on trust, and it holds exactly as described: git grep finds each variable only at its own assignment, never at a read. The three log lines are preserved, --version output is byte-identical, and the full suite (215 examples across six files) is green with this applied on top of the rate-limit work that landed in #11 — which touched the same function, so this was the one place a stale branch could have hurt. It merged clean.

Worth naming the part your summary undersold: auth_header was interpolating the API token into a string that nothing ever consumed. A dead variable holding a live secret is a little worse than dead weight — it is one set -x away from a token in a CI log. Removing it is a small security improvement, not only a tidy-up.

Also appreciated: keeping the interleaved logging while deleting the assignments, and rewriting the comment to say what the code now does instead of leaving it describing the removed variable. That is the part these cleanups usually get wrong.