test(smoke): use homebrew that’s already on runner

Homebrew is already installed:
https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md#package-management

.github/workflows/smoke-tests.yml

@@ -95,11 +95,10 @@ jobs:
           which shellspec
           shellspec --version
 
-      - name: Install brew on macOS
+      - name: Install test utilities with homebrew on macOS
         if: ${{ matrix.os == 'macos' }}
         # We need "timeout" and "jq" util and we'll use brew to check our brew package as well
         run: |
-          /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
           brew install coreutils
           brew install jq