chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/main.yml

@@ -21,7 +21,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: 🏗️ Create dummy install directories
         run: |
@@ -39,7 +39,7 @@ jobs:
           command: go version
 
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Run ShellSpec
         run: |
@@ -51,7 +51,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Run ShellCheck
         run: shellcheck bin/*