closure-compiler: drop obsolete tooling

Practically speaking, terser does a good enough job if not better wrt
minification.

diff --git a/.bin/closure-compiler b/.bin/closure-compiler
deleted file mode 100755 (executable)
index f41c573..0000000
--- a/.bin/closure-compiler
+++ /dev/null
@@ -1,2 +0,0 @@
-#!/bin/bash
-exec java -jar "/usr/local/src/extensions/closure/compiler.jar" "$@"