Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/reuse.yaml

@@ -10,6 +10,6 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: REUSE Compliance Check
       uses: fsfe/reuse-action@v5

.github/workflows/static.yml

@@ -29,7 +29,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Setup Node
         uses: actions/setup-node@v4
         with:

.github/workflows/update-api.yml

@@ -13,14 +13,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout this repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Checkout openstack-hypervisor-operator repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: cobaltcore-dev/openstack-hypervisor-operator
         path: openstack-hypervisor-operator
     - name: Checkout kvm-node-agent repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: cobaltcore-dev/kvm-node-agent
         path: kvm-node-agent