build(deps): 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/CI.yml

@@ -28,12 +28,12 @@ jobs:
           - { name: "pango", features: "v1_56", nightly: "", test_sys: true }
           - { name: "pangocairo", features: "", nightly: "--all-features", test_sys: true }
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ matrix.rust }}
           override: true
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           repository: gtk-rs/checker
           ref: main
@@ -106,7 +106,7 @@ jobs:
           - nightly
           - "1.86.0"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ matrix.rust }}
@@ -131,7 +131,7 @@ jobs:
     name: rust fmt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
@@ -146,14 +146,14 @@ jobs:
   cargo-deny:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: EmbarkStudios/cargo-deny-action@v2
 
   generator:
     name: regen check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
           set-safe-directory: true
@@ -170,7 +170,7 @@ jobs:
     name: docs embed check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
           set-safe-directory: true

.github/workflows/auto-update.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout current repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
 

.github/workflows/docs.yml

@@ -24,7 +24,7 @@ jobs:
         0.16=0.16
       RUSTDOCFLAGS: --cfg docsrs -Zunstable-options --generate-link-to-definition
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           submodules: recursive
           set-safe-directory: true

.github/workflows/typos.yml

@@ -10,6 +10,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Actions Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Check spelling
         uses: crate-ci/typos@master

.github/workflows/windows.yml

@@ -36,7 +36,7 @@ jobs:
 
       - name: (GTK binaries) checkout gvsbuild
         if: steps.cache.outputs.cache-hit != 'true'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: wingtk/gvsbuild
           ref: ${{ env.gvsbuildref }}
@@ -107,7 +107,7 @@ jobs:
           echo "C:\gtk-build\gtk\x64\release\bin" >> $GITHUB_PATH
         shell: bash
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions-rs/toolchain@v1
         with: