Keychain versions 2.9.0 and higher removed support for the --agents option and squawk in console constantly if the option isn't removed, now we check to make sure that the keychain version is less than 2.9.0 before passing the argument

Standards checklist:

• The PR title is descriptive.
• The PR doesn't replicate another PR which is already open.
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Changes:

• Changed the plugin to only pass --agents on versions lower than 2.9.0

Other comments:

I tested this with keychain v 2.9.5 on arch and it seems to work, however i'm not sure if the version output is the same on other operating systems, we could also just change this to not pass the option at all, or only pass the agents option if some flag is set or something, open to suggestions / criticisim