ci: Use bin/test and mise in test workflows

[sl0thentr0py]

• use mise entirely instead of setup-ruby in CI
• prewarm mise ruby cache with a new setup-mise action, cache of rubies shared across all workflows
• add --entry option to bin/test to enable direct json passthrough from matrix in CI
• replace individual gem workflows with single reusable gem_test workflow
• remove the rails group from resque - needless complexity
• not caching each cell's bundle for now since caches were too large anyway, will evaluate separately

[cursor]

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