remove unnecessary shell cmd

Author: kywch

.github/workflows/install.yml

@@ -8,9 +8,6 @@ jobs:
   test:
     name: test ${{ matrix.py }} - ${{ matrix.os }} - ${{ matrix.env }}
     runs-on: ${{ matrix.os }}
-    defaults:
-      run:
-        shell: bash -el {0}
     strategy:
       fail-fast: false
       matrix: