Fix the ref issue of the checkout action and sqlalchemy (#472)

* Remove head_ref from checkout action

* Fixed the svg errs in sqlalchemy

.github/workflows/build_icons.yml

@@ -6,8 +6,6 @@ jobs:
     runs-on: windows-2019
     steps:
       - uses: actions/checkout@v2
-        with:
-          ref: ${{ github.head_ref }}
       - name: Setup Python v3.8
         uses: actions/setup-python@v2
         with: 

.github/workflows/check_svgs.yml

@@ -6,8 +6,6 @@ jobs:
     runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
-        with:
-          ref: ${{ github.head_ref }}
       - name: Setup Python v3.8
         uses: actions/setup-python@v2
         with: 

.github/workflows/peek_icons.yml

@@ -9,8 +9,6 @@ jobs:
     runs-on: windows-2019
     steps:
       - uses: actions/checkout@v2
-        with:
-          ref: ${{ github.head_ref }}
       - name: Setup Python v3.8
         uses: actions/setup-python@v2
         with: