Actions: Use main branch (#417)

Author: ryonakano

.github/workflows/ci.yml

@@ -70,4 +70,4 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-    - uses: elementary/actions/vala-lint@master
+    - uses: elementary/actions/vala-lint@main

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Release
-        uses: elementary/actions/release@master
+        uses: elementary/actions/release@main
         env:
           GIT_USER_TOKEN: "${{ secrets.GIT_USER_TOKEN }}"
           GIT_USER_NAME: "elementaryBot"