Update actions/setup-python action to v3 (#120)

Co-authored-by: Renovate Bot <[email protected]>

Author: renovate[bot]

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python 3.7
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: 3.7
     - uses: actions/[email protected]

.github/workflows/format.yml

@@ -11,7 +11,7 @@ jobs:
           ref: ${{ github.head_ref }}
       - uses: actions/checkout@v2
       - name: Set up Python 3.7
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v3
         with:
           python-version: 3.7
       - name: Install formatter dependencies

.github/workflows/tests.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python 3.7
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: 3.7
     - uses: actions/[email protected]
@@ -56,7 +56,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python 3.7
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v3
         with:
           python-version: 3.7
       - uses: actions/[email protected]