Bump actions/checkout from 3 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...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/Android.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-22.04
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile RA
       run: |

.github/workflows/DOS-DJGPP.yml

@@ -20,7 +20,7 @@ jobs:
       options: --user root
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile RA
       run: |

.github/workflows/MSVC.yml

@@ -31,7 +31,7 @@ jobs:
             platform: x64
         # Qt and Cg builds are excluded for now
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Add msbuild to PATH
         uses: microsoft/setup-msbuild@v1

.github/workflows/MSYS2.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: windows-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up MSYS2
         uses: msys2/setup-msys2@v2

.github/workflows/MacOS.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: macos-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile RA
       run: |

.github/workflows/Miyoo.yml

@@ -20,7 +20,7 @@ jobs:
       options: --user root
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile RA
       run: |

.github/workflows/PS2.yml

@@ -20,7 +20,7 @@ jobs:
       options: --user root
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile Salamander
       run: |

.github/workflows/PS3-PSL1GHT.yml

@@ -20,7 +20,7 @@ jobs:
       options: --user root
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile Salamander
       run: |

.github/workflows/PS4-ORBIS.yml

@@ -20,7 +20,7 @@ jobs:
       options: --user root
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Install dependencies
       run: |

.github/workflows/PSP.yml

@@ -20,7 +20,7 @@ jobs:
       options: --user root
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
 
     - name: Compile bootstrap
       run: |