Bump actions/checkout from 2.3.5 to 2.4.0 (#452)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/codeql.yaml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🏗 Initialize CodeQL
         uses: github/codeql-action/init@v1
       - name: 🚀 Perform CodeQL Analysis

.github/workflows/labels.yaml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🚀 Run Label Syncer
         uses: micnncim/action-label-syncer@v1.3.0
         env:

.github/workflows/linting.yaml

@@ -65,7 +65,7 @@ jobs:
             name: Check YAML style
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🏗 Set up Python 3.8
         id: python
         uses: actions/setup-python@v2.2.2

.github/workflows/release.yaml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🏗 Set up Python 3.8
         id: python
         uses: actions/setup-python@v2.2.2

.github/workflows/tests.yaml

@@ -14,7 +14,7 @@ jobs:
         python: [3.8, 3.9]
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🏗 Set up Python ${{ matrix.python }}
         id: python
         uses: actions/setup-python@v2.2.2
@@ -59,7 +59,7 @@ jobs:
     needs: pytest
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: ⬇️ Download coverage data
         uses: actions/download-artifact@v2.0.10
       - name: 🏗 Set up Python 3.9

.github/workflows/typing.yaml

@@ -13,7 +13,7 @@ jobs:
         python: [3.8, 3.9]
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🏗 Set up Python ${{ matrix.python }}
         id: python
         uses: actions/setup-python@v2.2.2
@@ -56,7 +56,7 @@ jobs:
         python: [3.8, 3.9]
     steps:
       - name: ⤵️ Check out code from GitHub
-        uses: actions/checkout@v2.3.5
+        uses: actions/checkout@v2.4.0
       - name: 🏗 Set up Python ${{ matrix.python }}
         id: python
         uses: actions/setup-python@v2.2.2