Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/close-milestone.yml

@@ -42,7 +42,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           clean: 'false'
           fetch-depth: '0'

.github/workflows/draft-release.yml

@@ -48,7 +48,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           clean: 'false'
           fetch-depth: '0'

.github/workflows/lint.yml

@@ -45,7 +45,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           clean: 'false'
           fetch-depth: '0'

.github/workflows/update-milestone.yml

@@ -44,7 +44,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           clean: 'false'
           fetch-depth: '0'