security/zeek: Port improvements

• Remove useless BROKER option.
• Remove USES=ninja (now implied by USES=cmake).
• Make bison, flex, and swig hard dependencies.
• Strip several installed binaries.
• Remove some test files and directories mistakenly installed by spicy.
• While we're here, run portfmt.

Thanks to @diizzy for the bulk of these changes.

PR: 266345
Reported by: diizzy