bot: Update proposals candid bindings

[sa-github-api]

Motivation

We would like to render all the latest proposal types. Even with no changes, just updating the reference is good practice.

Changes

• Update the version of IC_COMMIT_FOR_PROPOSALS specified in dfx.json.
• Updated the proposals candid files to the versions in that commit.
• Updated the Rust code derived from .did files in the proposals payload rendering crate.

Tests

• [ ] Please check the API updates for any breaking changes that affect our code.
• [ ] Please check for new proposal types and add tests for them.

Breaking changes are:

• New mandatory fields
  • Removing mandatory fields
  • Renaming fields
  • Changing the type of a field
  • Adding new variants