Remove unused script run-plugin

The script was most a duplication of run-local and was
not actually used.

scripts/run-plugin

@@ -1,87 +0,0 @@
-#!/bin/bash
-
-set -o errexit
-
-option_copy=on
-pargs=()
-while [[ "$#" -gt 0 ]]; do
-  case $1 in
-    -keep)
-    option_copy=off
-    ;;
-    -global)
-    option_global=on
-    ;;
-    -*)
-    echo "error: unknown option \"$1\""
-    exit 1
-    ;;
-    *)
-    pargs+=("$1")
-    ;;
-  esac
-  shift
-done
-
-if [ "${#pargs[@]}" -lt 3 ]; then
-  echo "usage: $0 [options] <plugin-dir> <plugin-name> <build-dir>"
-  exit 1
-fi
-
-plugin_dir="${pargs[0]}"
-plugin="${pargs[1]}"
-
-if [[ "$OSTYPE" == "msys"* || "$OSTYPE" == "mingw"* ]]; then
-  run_windows=yes
-fi
-
-rundir=".run"
-bindir="$rundir/bin"
-datadir="$rundir/share/lite-xl"
-
-userdir="$(realpath "$rundir")"
-builddir="${pargs[2]}"
-
-build_lite () {
-  echo "running ninja"
-  ninja -C "$builddir"
-}
-
-copy_lite_build () {
-  echo "copying lite executable and data"
-  rm -fr "$rundir"
-  mkdir -p "$bindir" "$datadir"
-  if [ ! -z ${run_windows+x} ]; then
-    cp "$builddir/src/lite.exe" "$bindir"
-  else
-    cp "$builddir/src/lite" "$bindir"
-  fi
-  for module_name in core plugins colors fonts; do
-    cp -r "data/$module_name" "$datadir"
-  done
-}
-
-run_lite () {
-  if [ ! -z ${option_global+x} ]; then
-    echo "running \"lite ${pargs[@]:3}\""
-    exec "$bindir/lite" "${pargs[@]:3}"
-  else
-    echo "running \"lite ${pargs[@]:3}\" with local HOME"
-    if [ ! -z ${run_windows+x} ]; then
-      USERPROFILE="$userdir" exec "$bindir/lite" "${pargs[@]:3}"
-    else
-      HOME="$userdir" exec "$bindir/lite" "${pargs[@]:3}"
-    fi
-  fi
-}
-
-copy_plugin () {
-  echo "-- lite-xl 1.16" | cat - "$plugin_dir/$plugin.lua" > "$datadir/plugins/$plugin.lua"
-}
-
-if [ $option_copy == on ]; then
-  build_lite
-  copy_lite_build
-fi
-copy_plugin
-run_lite