MNT: attempt to fix CI

.github/workflows/build-book.yaml

@@ -41,6 +41,8 @@ jobs:
           DOCKER_REGISTRY: "ghcr.io"
           PUBLIC_REGISTRY_CHECK: true
           APPENDIX_FILE: "binder/appendix.txt"
+          REPO2DOCKER_EXTRA_ARGS: "--Repo2Docker.base_image=docker.io/library/buildpack-deps:bionic"
+          FORCE_REPO2DOCKER_VERSION: "2023.6.0"
 
   build-book:
     runs-on: ubuntu-latest

.github/workflows/link-checker.yaml

@@ -24,43 +24,25 @@ on:
         default: 'true'
         type: string
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   link-checker:
     runs-on: ubuntu-latest
     defaults:
       run:
         shell: bash -l {0}
     steps:
-      - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.11.0
-        with:
-          access_token: ${{ github.token }}
       - uses: actions/checkout@v4
-
-      - name: Setup Mambaforge
-        uses: conda-incubator/setup-miniconda@v2
+      - name: Setup Micromamba
+        uses: mamba-org/setup-micromamba@v1
         with:
-          miniforge-variant: Mambaforge
-          miniforge-version: latest
-          activate-environment: ${{ inputs.environment_name }}
-          use-mamba: true
-
-      - name: Set cache date
-        if: inputs.use_cached_environment == 'true'
-        run: echo "DATE=$(date +'%Y%m%d')" >> $GITHUB_ENV
-
-      - uses: actions/cache@v3
-        if: inputs.use_cached_environment == 'true'
-        with:
-          path: /usr/share/miniconda3/envs/${{ inputs.environment_name }}
-          key: linux-64-conda-${{ hashFiles('${{ inputs.environment_file }}') }}-${{ env.DATE }}
-        id: cache
-
-      - name: Update environment
-        if: |
-          inputs.use_cached_environment != 'true'
-          || steps.cache.outputs.cache-hit != 'true'
-        run: mamba env update -n ${{ inputs.environment_name }} -f ${{ inputs.environment_file }}
+          environment-name: ${{ inputs.environment_name }}
+          environment-file: ${{ inputs.environment_file }}
+          cache-environment: ${{ inputs.use_cached_environment }}
+          cache-environment-key: "linux-64-conda-${{ hashFiles('${{ inputs.environment_file }}') }}-${{ env.TODAY }}"
 
       - name: Disable notebook execution
         shell: python