Use bash shell to allow its idioms

Author: jneira

.github/workflows/test.yml

@@ -55,9 +55,11 @@ jobs:
                    src/**/*.hs exe/*.hs
 
     - name: Build
+      shell: bash
       # Retry it three times to workaround compiler segfaults in windows
       run: cabal build || cabal build || cabal build
     - name: Test
+      shell: bash
       env:
         HLS_TEST_EXE: hls
         HLS_WRAPPER_TEST_EXE: hls-wrapper