options: remove deprecated --playlist-pos alias

This causes problems because it has the same name as a property which
behaves differently.

DOCS/interface-changes.rst

@@ -42,6 +42,7 @@ Interface changes
       undeprecated or readded if it's not too much of a problem)
     - deprecate all input section commands (these will be changed/removed, as
       soon as mpv internals do not require them anymore)
+    - remove deprecated --playlist-pos alias (use --playlist-start)
  --- mpv 0.30.0 ---
     - add `--d3d11-output-format` to enable explicit selection of a D3D11
       swap chain format.

DOCS/man/input.rst

@@ -2735,10 +2735,6 @@ caveats with some properties (due to historical reasons):
     Strictly speaking, option access via API (e.g. ``mpv_set_option_string()``)
     has the same problem, and it's only a difference between CLI/API.
 
-``playlist-pos``, ``chapter``
-    These properties behave different from the deprecated options with the same
-    names.
-
 ``profile``, ``include``
     These are write-only, and will perform actions as they are written to,
     exactly as if they were used on the mpv CLI commandline. Their only use is

options/options.c

@@ -856,7 +856,6 @@ const m_option_t mp_opts[] = {
     OPT_REPLACED("input-unix-socket", "input-ipc-server"),
     OPT_REPLACED("softvol-max", "volume-max"),
     OPT_REMOVED("bluray-angle", "this didn't do anything for a few releases"),
-    OPT_REPLACED("playlist-pos", "playlist-start"),
     OPT_REPLACED("sub-text-font", "sub-font"),
     OPT_REPLACED("sub-text-font-size", "sub-font-size"),
     OPT_REPLACED("sub-text-color", "sub-color"),