Publish schema for GBFS v3.1-RC2

[richfab]

Context

GBFS v3.1-RC2 will be released in May 2025, as per the version release cycles from the governance.

To do (once v3.1-RC2 is released)

• Create a new schema 'v3.1-RC2' with the proposed spec changes (see changelog) --> version 3.1-RC2 release #166
• Use the GitHub raw links for the schema $id values to avoid using # fragments in the uri: e.g. "$id": "https://raw.githubusercontent.com/MobilityData/gbfs-json-schema/refs/heads/master/v3.1-RC2/gbfs.json" (this was first raised in fix schema ids #161)
• Replace v3.1-RC by v3.1-RC2 in the gbfs-validator repo --> feat: 198 update to v31 rc2 schema gbfs-validator#204
• Remove v3.1-RC from the gbfs-json-schema repo --> Remove v3.1-RC JSON Schema (replaced by v3.1-RC2) #170
• Update Go model to v3.1-RC2
• Update Java model to v3.1-RC2
• Update Rust model to v3.1-RC2
• Update TypeScript model to v3.1-RC2

[davidgamez]

Task:

• Merge RC2 into the current official RC version comment

Validator Reference