Update actions/checkout action to v6

.github/workflows/integration_test.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0
       - name: Check libs
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
       - name: Setup LXD
         uses: canonical/setup-lxd@main
@@ -75,7 +75,7 @@ jobs:
       suites: ${{ steps.suites.outputs.suites }}
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
       - name: Install charmcraft
         run: sudo snap install charmcraft --classic
@@ -102,7 +102,7 @@ jobs:
         suite: ${{ fromJSON(needs.define-matrix.outputs.suites) }}
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
       - name: Download charm artifact
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4

.github/workflows/lint.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - name: Install dependencies
         run: sudo snap install --classic astral-uv
       - name: Run linters

.github/workflows/promote-charm.yml

@@ -40,7 +40,7 @@ jobs:
             exit 1
           fi
       - name: Checkout
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           persist-credentials: false
       - name: Promote Charm

.github/workflows/publish.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -36,7 +36,7 @@ jobs:
       - build-and-publish-image
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Upload charm to charmhub
         uses: canonical/charming-actions/upload-charm@1753e0803f70445132e92acd45c905aba6473225

.github/workflows/unit_test.yml

@@ -8,7 +8,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install uv
         uses: astral-sh/setup-uv@v5
@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Install tox
         run: sudo apt-get install -y python3.12 tox