Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/linter.yml

@@ -15,7 +15,7 @@
       runs-on: ubuntu-latest
       steps:
         - name: Checkout
-          uses: actions/checkout@v5
+          uses: actions/checkout@v6
 
         - name: PHP syntax checker 8.2
           uses: prestashop/github-action-php-lint/8.2@master
@@ -25,7 +25,7 @@
   #    runs-on: ubuntu-latest
   #    steps:
   #      - name: Checkout
-  #        uses: actions/checkout@v5
+  #        uses: actions/checkout@v6
   #        
   #      - name: PHP Mess Detector
   #        uses: php-actions/phpmd@v1
@@ -40,7 +40,7 @@
       runs-on: ubuntu-latest
       steps:
         - name: Checkout
-          uses: actions/checkout@v5
+          uses: actions/checkout@v6
 
         - name: PHP Code Sniffer
           uses: php-actions/phpcs@v1
@@ -59,12 +59,12 @@
   #    runs-on: ubuntu-latest
   #    steps:
   #      - name: Checkout
-  #        uses: actions/checkout@v5
+  #        uses: actions/checkout@v6
   #        with:
   #          path: src
   #
   #      - name: Checkout Heimdall repo for dependencies
-  #        uses: actions/checkout@v5
+  #        uses: actions/checkout@v6
   #        with:
   #          repository: linuxserver/Heimdall
   #          path: ./heimdall-src

.github/workflows/main.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup node env
         uses: actions/setup-node@v6

.github/workflows/prchecks.yml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup node env
         uses: actions/setup-node@v6

.github/workflows/svgo.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Optimize SVGs
         uses: ericcornelissen/svgo-action@v4
         id: svgo