Changes CI build to only handle branches, not tag pushes

Author: i8beef

.github/workflows/build.yml

@@ -1,5 +1,11 @@
 name: build
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - "**"
+  pull_request:
+    branches:
+      - "**"
 
 env:
   DOTNETVERSION: "5.0.x"