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/cmake.yml

@@ -24,7 +24,7 @@ jobs:
         link: ["STATIC", "SHARED"]
     steps:
       - name: Checkout Drogon source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           submodules: true
           fetch-depth: 0
@@ -73,7 +73,7 @@ jobs:
         osver: [14, 15]
     steps:
       - name: Checkout Drogon source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           submodules: true
           fetch-depth: 0
@@ -156,7 +156,7 @@ jobs:
       CXX: ${{ matrix.compiler.cxx }}-${{ matrix.compiler.ver }}
     steps:
       - name: Checkout Drogon source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           submodules: true
           fetch-depth: 0

.github/workflows/codeql.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
     - name: Checkout Drogon source code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: true
         fetch-depth: 0

.github/workflows/codespell.yml

@@ -10,6 +10,6 @@ jobs:
   codespell:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - run: sudo apt-get install -y codespell
     - run: codespell --ignore-words-list="coo,folx,ot,statics,xwindows,NotIn,aNULL," --skip="*.csp"

.github/workflows/cpp.yml

@@ -12,7 +12,7 @@ jobs:
   format:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install dos2unix
         run: sudo apt-get install -y dos2unix
@@ -32,7 +32,7 @@ jobs:
   cpplint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install cpplint
         run: pip install cpplint

.github/workflows/docker-publish.yml

@@ -10,7 +10,7 @@ jobs:
 
     steps:
       - name: Check out code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Log in to Docker Hub
         uses: docker/login-action@v3