remove ref from checkout (#82)

Author: pavelzw

template/.github/workflows/ci.yml

@@ -14,8 +14,6 @@ jobs:
     steps:
       - name: Checkout branch
         uses: actions/checkout@v4
-        with:
-          ref: ${{ github.head_ref }}
       - name: Run pre-commit-conda
         uses: quantco/pre-commit-conda@v1
   env:
@@ -24,8 +22,6 @@ jobs:
     steps:
       - name: Checkout branch
         uses: actions/checkout@v4
-        with:
-          ref: ${{ github.head_ref }}
       - name: Set up Conda env
         uses: mamba-org/setup-micromamba@0dea6379afdaffa5d528b3d1dabc45da37f443fc
         with: