Build binaries only for tags

This is to reduce the usage of GitHub Actions. I did not look into the pricing of GitHub Actions. If
it is based on the amount of build time that is consumed, then I want to consume less by building
only tags.

.github/workflows/build-binary.yml

@@ -1,6 +1,8 @@
 name: Build Binary
 
-on: [push]
+on:
+  push:
+    tags:
 
 jobs:
   build: