mac-videotoolbox: Remove obsolete translation

A commit e461ec4be1 added a translation key "VTEncoder" but never used.

plugins/mac-videotoolbox/data/locale/en-US.ini

@@ -5,7 +5,6 @@ VTHEVCEncT2="Apple VT HEVC T2 Hardware Encoder"
 VTHEVCEncSW="Apple VT HEVC Software Encoder"
 VTProResEncHW="Apple VT ProRes Hardware Encoder"
 VTProResEncSW="Apple VT ProRes Software Encoder"
-VTEncoder="VideoToolbox Encoder"
 Bitrate="Bitrate"
 Quality="Quality"
 UseMaxBitrate="Limit bitrate"