chore(deps): update actions/checkout action to v6 (#171)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/build-test.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     container: condaforge/miniforge3:latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: false
@@ -27,7 +27,7 @@ jobs:
     runs-on: ubuntu-latest
     container: python:3.9
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: false

.github/workflows/release.yaml

@@ -18,7 +18,7 @@ jobs:
       release_version: ${{ steps.check-release.outputs.release_version }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: false
@@ -41,7 +41,7 @@ jobs:
       WHEEL_OUTPUT_DIR: /tmp/wheel_output
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: false