Upgrade checkout action in workflows to v4 (#1106)

> This is an automatically generated PR.

actions/checkout got a new release with v4. Shouldn't affect anything, just newer.

@rebuy-de/it-platform FYI

.github/workflows/ci.yaml

@@ -21,7 +21,7 @@ jobs:
       run: |
         go install golang.org/x/lint/golint@latest
     - name: Checkout code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Check Formatting
       run: |
         if [ "$(gofmt -s -l . | wc -l)" -gt 0 ]; then
@@ -42,7 +42,7 @@ jobs:
     if: github.event_name != 'pull_request' || (github.event.pull_request.head.repo.full_name == 'rebuy-de/aws-nuke' && github.event.pull_request.user.login != 'dependabot[bot]')
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         fetch-depth: 0
 

.github/workflows/release.yaml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
     - name: Checkout code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0
         ref: main
@@ -40,7 +40,7 @@ jobs:
       with:
         go-version: '1.21'
     - name: Checkout code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0
     - name: Build Project binaries
@@ -62,7 +62,7 @@ jobs:
     name: Docker Build
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         fetch-depth: 0