Add rubygems support

[bitterpanda63]

Summary by Aikido

Security Issues: 0	🔍 Quality Issues: 1	Resolved Issues: 0

🚀 New Features

• Added RubyGems package firewall rule, parser, tests, and integration

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[aikido-pr-checks]

Added ruby_policy which duplicates the existing per-ecosystem policy match blocks; this repeats substantial logic and JSON structure already present.

Details

✨ AI Reasoning
​​1) The change adds a new ruby_policy match block that mirrors existing per-ecosystem policy match blocks.
​2) This repeats the same logical pattern and JSON shape used for other ecosystems.
​3) The repetition increases maintenance burden because fixes to policy-shape handling would need multiple places updated.
​4) The duplication is within the same file and was introduced by this PR.

🔧 How do I fix it?
Delete extra code. Extract repeated code sequences into reusable functions or methods. Use loops or data structures to eliminate repetitive patterns.

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