chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ests.yml

@@ -10,7 +10,7 @@ jobs:
     permissions:
       contents: write # committing
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
         with:
           ref: ${{ github.head_ref }}
       - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0

.github/workflows/main.yml

@@ -15,7 +15,7 @@ jobs:
       contents: write # committing
       models: read # summarise
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
       # azure-identity doesn't support GitHub WIF
       - uses: azure/login@a65d910e8af852a8061c627c456678983e180302 # v2.2.0
         with: