use --installed option while executing brew

[skaji]

Description

I created #81, where I suggested that we can use brew --prefix openssl to probe openssl libraries. But it turns out that brew --prefix openssl prints a directory even if openssl formula is not installed. I'm sorry.

❯ brew --prefix --help
Usage: brew --prefix [--unbrewed] [--installed] [formula ...]
...
If formula is provided, display the location where formula is or would be
installed.
...
      --installed                  Outputs nothing and returns a failing
                                   status code if formula is not installed.

This PR adds --installed option to brew --prefix command so that brew --prefix prints a directory only if openssl formula is actually installed.

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules
• [x] Changes have been manually tested (please provide information on test platform using the fields below)

Test / Development Platform Information

• Operating system and version: macOS / linux
• Crypt::OpenSSL::X509 version: 1.906
• Perl version: 5.32.1
• OpenSSL version: 1.1.1k