fix: forward skip_flag to syncplay player invocation

[TheMridul]

Summary

• --skip computes skip_flag via ani-skip and forwards it to the *mpv* and *flatpak*mpv* player branches in play_episode(), but the *yncpla* (syncplay) branch never included it, so combining -s/--syncplay with --skip silently did nothing.
• Adds $skip_flag to the syncplay invocation's player-args passthrough (after --), matching the other mpv-based branches.

Test plan

• Ran ani-cli -s --skip "<anime>" with ani-skip installed and confirmed intro is skipped when launched via syncplay.
• Confirmed plain ani-cli --skip "<anime>" (no syncplay) still skips intros as before.

[port19x]

I'm very interested in this change.
If you used AI in making this, which I don't want to accuse you of, but from the text it sounds a little like it, please add the used AI as a coauthor

[TheMridul]

Bumped to 5.0.3 — thanks for catching that, I missed it in CONTRIBUTING.

On the AI question, fair to ask. The bug and the fix are mine: I hit it running -s together with --skip, noticed intro-skipping silently did nothing, and traced it to the syncplay branch being the only player branch that never forwarded $skip_flag. The one-line change is hand-written.

What I did put through an AI was the PR description, which is almost certainly what you picked up on. The version bump commit I just pushed was also AI-written, so that one carries a Co-Authored-By trailer. Happy to squash it into the fix or restructure the commits however you prefer.