[CI] Update branch references to only include master in workflow

Author: KarhouTam

.github/workflows/ci.yml

@@ -2,9 +2,21 @@ name: CI
 
 on:
   push:
-    branches: [main, master]
+    branches: [master]
+    paths:
+      - 'src/**'
+      - 'tests/**'
+      - '.github/workflows/ci.yml'
+      - 'requirements.txt'
+      - 'pyproject.toml'
   pull_request:
-    branches: [main, master]
+    branches: [master]
+    paths:
+      - 'src/**'
+      - 'tests/**'
+      - '.github/workflows/ci.yml'
+      - 'requirements.txt'
+      - 'pyproject.toml'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}