Update Temporal Cloud-API to v0.12.0

[chndler]

What was changed

• Update Temporal cloud-api to v0.12.0
• Add protoc-gen-openapiv2 protos to support api-cloud v0.12.0

Why?

Checklist

1. Closes

2. How was this tested:

3. Any docs updates needed?

---

Note

Low Risk
Low risk: changes are limited to build configuration and added .proto descriptor/option definitions; primary risk is build/proto-generation breakage due to new third-party protos or source-set ordering/exclusions.

Overview
Updates temporal-serviceclient proto generation to include a new src/main/proto-thirdparty source directory.

Vendors gRPC-Gateway protoc-gen-openapiv2 option protos (annotations.proto, openapiv2.proto) so the project can compile against newer Temporal Cloud API protos that reference these OpenAPI annotations.

^{Written by Cursor Bugbot for commit 5791937. This will update automatically on new commits. Configure here.}

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[mjameswh]

@chndler This PR adds third party protos, but doesn't modify the cloud protos at all.

Is that really what you meant to do? If so, how are those extra protos useful to us?

[chndler]

@chndler This PR adds third party protos, but doesn't modify the cloud protos at all.

Is that really what you meant to do? If so, how are those extra protos useful to us?

@mjameswh sorry about that, fixed by updating cloud protos