Hygiene: remove unused pre-commit script

dev-scripts/pre-commit is unused since 5037568 which added the
pre-commit NPM package. Remove the script.

Change-Id: I7b7e11415dc6ada17a5fe6bc1a390cc5de80851a

dev-scripts/pre-commit

@@ -1,75 +0,0 @@
-#!/usr/bin/env bash
-# Enable this pre-commit hook by running 'make installhooks'
-set -euo pipefail
-
-git-staged-files() {
-	git diff --cached -C -C -z --name-only --diff-filter=ACMRTUXB "$@"
-}
-
-git-is-staged() {
-	local diff=0
-	git-staged-files --quiet "$@" 2> /dev/null || diff=$?
-	[[ diff -eq 1 ]] || return 1
-}
-
-map() { IFS= read -rd $'\0' "$@"; }
-
-compress-png() {
-	git-staged-files \*.png|while map file; do
-		echo "Compressing $file"
-		optipng -q -o7 "$file" && advpng -z -4 "$file" && advdef -z -4 "$file" | grep Output
-		git add "$file"
-	done
-}
-
-compress-svg() {
-	git-staged-files \*.svg|while map file; do
-		make nodecheck
-		echo "Compressing $file"
-		node_modules/.bin/svgo --config=.svgo.yml "$file"
-		git add "$file"
-	done
-}
-
-test-whitespace() { git diff --cached --check; }
-
-test-js() {
-	local err=0
-
-	make eslint || err+=1
-
-	if git-is-staged \*.js; then
-		make qunit || err+=1
-	fi
-
-	return $err
-}
-
-test-php() {
-	local err=0
-	if git-is-staged \*.php; then
-		make phplint || err+=1
-	fi
-
-	# todo: where is result set?
-	if git-is-staged 'includes/skins/*.php'; then
-		make validatehtml > $result || err+=1
-	fi
-
-	return $err
-}
-
-main() {
-	local err=0
-
-	compress-png
-	compress-svg
-
-	test-whitespace || err+=1
-	test-js || err+=1
-	test-php || err+=1
-
-	return $err
-}
-
-main "$@"