Bump actions/checkout from 2 to 2.3.4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 2.3.4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v2.3.4)

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

.github/workflows/build-master.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
 
       - name: Check out
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Get time
         uses: gerred/actions/current-time@master

.github/workflows/codeql-analysis.yml

@@ -39,7 +39,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@v2.3.4
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL

.github/workflows/docker.yaml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Check out
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Get tag
         uses: olegtarasov/get-tag@v2

.github/workflows/release.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
 
       - name: Check out
-        uses: actions/checkout@v2
+        uses: actions/checkout@v2.3.4
 
       - name: Get tag
         uses: olegtarasov/get-tag@v2