icons: Remove media-playback-start-symbolic-rtl

See https://gitlab.gnome.org/GNOME/adwaita-icon-theme/-/issues/101

gtk/icons/scalable/actions/media-playback-start-symbolic-rtl.svg

@@ -1,6 +0,0 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16">
-    <g color="#000" fill="#474747">
-        <path d="M10.967 3a1 1 0 0 0-.467.13l-6.996 4a1 1 0 0 0 0 1.74l6.996 4a1 1 0 0 0 1.498-.87V4a1 1 0 0 0-1.03-1zm-.969 2.725v4.55L6.018 8z" style="line-height:normal;font-variant-ligatures:normal;font-variant-position:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-alternates:normal;font-feature-settings:normal;text-indent:0;text-align:start;text-decoration-line:none;text-decoration-style:solid;text-decoration-color:#000;text-transform:none;text-orientation:mixed;shape-padding:0;isolation:auto;mix-blend-mode:normal;marker:none" font-weight="400" font-family="sans-serif" white-space="normal" overflow="visible"/>
-        <path d="M10.998 12h1v1h-1zM10.998 3h1v1h-1zM10.998 4L4 8l6.998 4z" style="marker:none" overflow="visible"/>
-    </g>
-</svg>