Bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
           sudo rm -rf /usr/local/lib/android
           sudo rm -rf /opt/ghc
       - name: checkout code
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
       - name: setup java
         uses: actions/setup-java@v5.2.0
         with:
@@ -71,7 +71,7 @@ jobs:
       OPEN_API_TEST: "true"
     steps:
       - name: checkout code
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
       - name: setup java
         uses: actions/setup-java@v5.2.0
         with:
@@ -93,14 +93,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout code
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
       - name: Build docker image
         run: docker build -t cda:build-latest .
   build-schema-migration-image:
     runs-on: ubuntu-latest
     steps:
       - name: checkout code
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
       # No uploads, we're just verifying that nothing broke the docker image.
       - name: Build Migration image
         uses: ./.github/actions/database-migration-image
@@ -118,7 +118,7 @@ jobs:
     if: always() && (github.ref_name == 'develop')
     steps:
       - name: Badge Branch
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
         with:
           ref: badges
           fetch-depth: 1

.github/workflows/codeql.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v3.29.11

.github/workflows/release.yml

@@ -57,7 +57,7 @@ jobs:
           sudo rm -rf /usr/local/lib/android
           sudo rm -rf /opt/ghc
       - name: checkout code
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6
         with:
           ref: ${{inputs.branch}}
       - name: setup java

.github/workflows/web-gui-checks.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: install node for cda-gui audit
         uses: actions/setup-node@v4