ci: update default branch

.github/workflows/ci.yml

@@ -1,12 +1,12 @@
 name: CI
 on:
   push:
-    branches: [master]
+    branches: [main]
     paths-ignore:
       - 'README.md'
       - 'docs/**'
   pull_request:
-    branches: [master]
+    branches: [main]
     paths-ignore:
       - 'README.md'
       - 'docs/**'
@@ -76,7 +76,7 @@ jobs:
           DOCKERHUB_REPOSITORY: peterevans/dd-ci-fixture-${{ matrix.target }}
 
   package:
-    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     needs: [test]
     runs-on: ubuntu-latest
     steps:
@@ -91,7 +91,7 @@ jobs:
           commit-message: 'build: update distribution'
           title: Update distribution
           body: |
-            - Updates the distribution for changes on `master`
+            - Updates the distribution for changes on `main`
 
             Auto-generated by [create-pull-request][1]