repo: Update prost and pbjson crates

[smalis-msft]

These are quite old, but we've had issues updating them in the past. Let's try again.

[Copilot]

Pull request overview

Updates the workspace’s protobuf toolchain dependencies (prost + pbjson) and adjusts enum conversion call sites to match newer APIs.

Changes:

• Bump prost/* from 0.11 to 0.14 and pbjson* from 0.5 to 0.9.
• Replace from_i32(...) enum decoding with try_from(...) and updated error handling.
• Remove the temporary pbjson-build patch override.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
vm/devices/tdisp_proto/src/lib.rs	Updates enum decoding to try_from(...).ok() for new prost enum API.
vm/devices/tdisp/src/serialize_proto.rs	Updates validation macro to use try_from and map conversion failures into anyhow errors.
vm/devices/tdisp/src/lib.rs	Updates request handling code paths to match try_from’s Result return type.
vm/devices/get/underhill_config/src/schema/v1.rs	Updates version parsing to try_from while preserving “Unknown” fallback behavior.
Cargo.toml	Bumps prost/pbjson versions and removes the pbjson-build git patch override.

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At least one Petri test failed.