gha: remove env vars SHELL

.github/workflows/tests.yaml

@@ -8,9 +8,6 @@ on:
     - cron: '5 1 * * *'  # every day at 01:05
   workflow_dispatch:
 
-env:
-  SHELL: /bin/bash
-
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true

tests/func/test_repro.py

@@ -776,7 +776,8 @@ def test_cmd_repro(tmp_dir, copy_script, run_stage):
 
 
 @pytest.mark.skipif(os.name == "nt", reason="not on nt")
-def test_repro_shell(tmp_dir, dvc):
+def test_repro_shell(tmp_dir, monkeypatch, dvc):
+    monkeypatch.setenv("SHELL", "/bin/sh")
     dvc.run(
         fname="shell.txt.dvc",
         outs=["shell.txt"],