Fix incorrect and missing metadata in style spec reference

[tristen]

Fixed "requires" entry for fill-pattern-cross-fade and fill-extrusion-pattern-cross-fade which were both falsely reporting line-pattern as a requirement.

Fixed "sdk-support"entry for model-allow-density-reduction. This previously referenced very old versions where models were not supported.

Added "units": "pixels" to:

• line-border-width

Added "units": "meters" to:

• symbol-z-offset
• fill-z-offset
• model-translation
• fill-extrusion-edge-radius
• building-facade-unit-width
• fill-extrusion-ambient-occlusion-ground-radius
• building-ambient-occlusion-ground-radius
• fog.vertical-range

Added "units": "degrees" to:

• sky-gradient-radius
• hillshade-illumination-direction

Removed "units": "pixels" to:

• building-flip-roof-orientation as this is a boolean

[github-actions]

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