[condalock] update conda lock creation Github Action workflow and ship updated (bot-generated) conda-lock file

.github/workflows/create-condalock-file.yml

@@ -6,10 +6,15 @@ on:
   # and hence lots of automated PRs
   # push:
   #   branches:
-  #     - condalock-update
+  #     - main
   schedule:
     - cron: '0 4 */10 * *'
 
+# Required shell entrypoint to have properly configured bash shell
+defaults:
+  run:
+    shell: bash -l {0}
+
 jobs:
   create-lock-file:
     name: Create conda lock file for latest Python
@@ -27,50 +32,49 @@ jobs:
           miniforge-variant: Mambaforge
           use-mamba: true
       - name: Show conda config
-        shell: bash -l {0}
         run: |
           conda update -n base -c conda-forge conda
-          conda info
-          conda list
+          conda --version
+          # setup-miniconda@v2 installs an old conda and mamba
+          # forcing a modern mamba updates both mamba and conda
+          conda install -c conda-forge "mamba>=1.4.8"
           conda config --show-sources
           conda config --show
+          conda --version
+          mamba --version
       - name: Python info
-        shell: bash -l {0}
         run: |
           which python
           python --version
       - name: Install conda-lock
-        shell: bash -l {0}
-        run: mamba install -y conda-lock
+        run: mamba install -y -c conda-forge conda-lock
       - name: Check version of conda-lock
-        shell: bash -l {0}
         run: conda-lock --version
       - name: Create conda lock file for linux-64
-        shell: bash -l {0}
         run: conda-lock lock --platform linux-64 -f environment.yml --mamba --kind explicit
-      - shell: bash -l {0}
+      - name: Show conda version again
         run: conda --version
-      - shell: bash -l {0}
-        run: which python
-      - shell: bash -l {0}
-        run: python -V
-      - shell: bash -l {0}
+      - name: Show Python exec and version again
+        run: |
+          which python
+          python -V
+      - name: Create conda-lock environment
         run: conda create --name esmvaltool-fromlock --file conda-linux-64.lock
-      - shell: bash -l {0}
+      - name: Install pip
         run: mamba install -y pip
-      - shell: bash -l {0}
-        run: which python
-      - shell: bash -l {0}
-        run: pip --version
-      - shell: bash -l {0}
+      - name: Check Python and pip versions post pip-install
+        run: |
+          which python
+          pip --version
+      - name: Install ESMValTool
         run: pip install -e .[develop]
-      - shell: bash -l {0}
+      - name: Check ESMValTool version
         run: esmvaltool --help
-      - shell: bash -l {0}
+      - name: Check ESMValTool help
         run: esmvaltool version
-      - shell: bash -l {0}
+      - name: Run flake8
         run: flake8
-      - shell: bash -l {0}
+      - name: Run tests
         run: pytest -n 2 -m "not installation"
       # Automated PR
       # see https://github.com/marketplace/actions/create-pull-request