Update actions/checkout action to v6 (#21)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
       matrix:
         os: ["ubuntu-latest", "macos-latest", "windows-latest", "macos-13"]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
       - uses: crystal-lang/install-crystal@v1
@@ -63,7 +63,7 @@ jobs:
       matrix:
         os: ["ubuntu-22.04-arm", "ubuntu-24.04-arm"]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
       - name: Install crystal
@@ -93,7 +93,7 @@ jobs:
     name: MinGW64
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
       - uses: msys2/setup-msys2@v2

.github/workflows/docs.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: crystal-lang/install-crystal@v1
       - name: Install dependencies
         run: shards install

.github/workflows/md5checker.yml

@@ -16,7 +16,7 @@ jobs:
     name: Build DEB Package (Ubuntu)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
 
@@ -56,7 +56,7 @@ jobs:
       matrix:
         os: [macos-latest, macos-13]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
 
@@ -91,7 +91,7 @@ jobs:
     name: Build Windows Installer
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
 
@@ -132,7 +132,7 @@ jobs:
     name: Build MinGW64
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: true
 

.github/workflows/screenshot.yml

@@ -29,7 +29,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
 
@@ -117,7 +117,7 @@ jobs:
     if: github.ref == 'refs/heads/main'
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true