changing ghaction build action to run on the main branch

.github/workflows/build.yml

@@ -2,9 +2,9 @@ name: Artifact Build
 
 on:
   push:
-    branches: [ ghaction ]
+    branches: [ main ]
   pull_request:
-    branches: [ ghaction ]
+    branches: [ main ]
 
 jobs:
   build:
@@ -21,5 +21,5 @@ jobs:
         run: npm install
       - name: Run linter
         run: npm run lint:js
-      - name: Build XPI        
+      - name: Build XPI
         run: npm run build