Update actions/checkout requirement to v2.3.4 (#46)

Updates the requirements on [actions/checkout](https://github.com/actions/checkout) to permit the latest version.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/commits/5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f)

Signed-off-by: dependabot[bot] <support@github.com>

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

.github/workflows/check.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v2.3.3
+        uses: actions/checkout@v2.3.4
 
       - name: Set up Python 3.x
         uses: actions/setup-python@v2

.github/workflows/docs.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v2.3.3
+        uses: actions/checkout@v2.3.4
 
       # See https://github.com/warner/python-versioneer/issues/206
       - name: Fetch all history for all tags and branches

.github/workflows/format-command.yml

@@ -10,7 +10,7 @@ jobs:
   black:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v2.3.4
         with:
           token: ${{ secrets.PAT }}
           repository: ${{ github.event.client_payload.pull_request.head.repo.full_name }}

.github/workflows/pypi-publish.yml

@@ -14,7 +14,7 @@ jobs:
     if: github.repository == 'seisman/HinetPy'
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2.3.4
 
     - name: Set up Python
       uses: actions/setup-python@v2

.github/workflows/tests.yml

@@ -31,7 +31,7 @@ jobs:
           access_token: ${{ github.token }}
 
       - name: Checkout
-        uses: actions/checkout@v2.3.3
+        uses: actions/checkout@v2.3.4
 
       # See https://github.com/warner/python-versioneer/issues/206
       - name: Fetch all history for all tags and branches