Add support for keyring in macOS tests

[BartoszCiesla]

Install and configure needed SW in macOS pipeline (https://github.com/iggy-rs/iggy/blob/master/.github/workflows/test_pr.yml#L103) and enable 2 test cases (which are disabled for macOS only right now)

• integration/tests/cli/personal_access_token/mod.rs
• integration/tests/cli/system/mod.rs

Error reported by keyring crate on macOS whith missing keyring setup in the OS:

---- cli::personal_access_token::test_pat_login_options::should_be_successful stdout ----
thread 'cli::personal_access_token::test_pat_login_options::should_be_successful' panicked at integration/tests/cli/personal_access_token/test_pat_login_options.rs:82:14:
Failed to set token: PlatformFailure(Error { code: -25308, message: "User interaction is not allowed." })