CI: use conda-initialized bash for the whole tests workflow

Author: crusaderky

.github/workflows/tests.yaml

@@ -13,6 +13,11 @@ concurrency:
   group: tests-${{ github.ref }}
   cancel-in-progress: true
 
+# Required shell entrypoint to have properly activated conda environments
+defaults:
+  run:
+    shell: bash -l {0}
+
 jobs:
   test:
     # Do not run the schedule job on forks
@@ -111,7 +116,6 @@ jobs:
           # export TEST_ID="$TEST_ID-${{ matrix.run }}"
           echo "TEST_ID: $TEST_ID"
           echo "TEST_ID=$TEST_ID" >> $GITHUB_ENV
-        shell: bash
 
       - name: Checkout source
         uses: actions/checkout@v4.1.3
@@ -127,7 +131,6 @@ jobs:
           activate-environment: dask-distributed
 
       - name: Show conda options
-        shell: bash -l {0}
         run: conda config --show
 
       - name: Check if caching is enabled
@@ -145,7 +148,6 @@ jobs:
           )
         id: get-date
         run: echo "::set-output name=today::$(/bin/date -u '+%Y%m%d')"
-        shell: bash
 
       - name: Cache Conda env
         if: steps.skip-caching.outputs.trigger-found != 'true'
@@ -254,7 +256,6 @@ jobs:
 
       - name: Generate junit XML report in case of pytest-timeout
         if: ${{ failure() }}
-        shell: bash -l {0}
         run: |
           if [ ! -e reports/pytest.xml ]
           then
@@ -277,7 +278,6 @@ jobs:
           always() &&
           (steps.run_tests.outcome == 'success' || steps.run_tests.outcome == 'failure') &&
           matrix.os != 'windows-latest'
-        shell: bash -l {0}
         run: sed -i'' -e 's/filename="/filename="distributed\//g' coverage.xml
 
       # Do not upload coverage reports for cron jobs