fix: remove unnecessary shell specification in setup steps

Author: oorabona

.github/actions/setup-env/action.yml

@@ -24,7 +24,6 @@ runs:
   steps:
     - name: Setup pnpm
       uses: pnpm/action-setup@v4
-      shell: bash
 
     - name: Setup Node.js ${{ inputs.node-version }}
       uses: actions/setup-node@v4
@@ -43,7 +42,6 @@ runs:
 
     - name: Cache pnpm store
       uses: actions/cache@v4
-      shell: bash
       with:
         path: |
           ~/.local/share/pnpm/store