Update pyproject-fmt to 2.15.2

[adamtheturtle]

Update pyproject-fmt to 2.15.2.

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Note

Low Risk
Dev-tool version bump plus a config ordering/formatting tweak in pyproject.toml; no runtime code paths or production dependencies are affected.

Overview
Bumps the dev dependency pyproject-fmt from 2.14.2 to 2.15.2.

Also adjusts pyproject.toml formatting by moving coverage’s run.branch = true to match the tool’s expected ordering, with no functional configuration change intended.

^{Written by Cursor Bugbot for commit f359c31. This will update automatically on new commits. Configure here.}