Remove deprecated token event format from soroban-token-sdk (#1822)

### What

Removes the deprecated event format from the `soroban-token-sdk`. These
were originally deprecated for the v23 release.

### Why

Closes #1775 

### Known limitations

None

---------

Co-authored-by: Siddharth Suresh <siddharth@stellar.org>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: sisuresh <5050166+sisuresh@users.noreply.github.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Dmytro Kozhevin <dmytro@stellar.org>
Co-authored-by: Jay Geng <jay@stellar.org>

Author: 6 people

.github/workflows/rust.yml

@@ -12,6 +12,7 @@ concurrency:
 
 env:
   ARTIFACT_RETENTION_DAYS_FOR_TEST_WASMS: 7
+  SOROBAN_SDK_BUILD_SYSTEM_SUPPORTS_SPEC_SHAKING_V2: 1
 
 defaults:
   run:

soroban-token-sdk/src/_migrating.rs

@@ -1,3 +1,10 @@
+//! # Migrating from v23 to v26
+//!
+//! 1. Remove the deprecated event format. For details, see the [migration guide for v23 contract events].
+//!    And for an example using the `soroban_token_sdk` directly, see the [migration guide for v23 token transfer][v23_token_transfer].
+//!
+//! [migration guide for v23 contract events]: soroban_sdk::_migrating::v23_contractevent
+//!
 //! # Migrating from v22 to v23
 //!
 //! 1. [`MuxedAddress` replaces `Address` as the `to` of the `TokenInterface::transfer`][v23_token_transfer]

soroban-token-sdk/src/_migrating/v23_token_transfer.rs

@@ -16,9 +16,12 @@
 //! the exchange deposits for the token contracts, but is necessary for that.
 //!
 //! The necessary token modification is very minimal. Consider the following
-//! `transfer` implementation that still uses `Address` destination:
+//! `transfer` implementation that still uses `Address` destination. Note that
+//! this example will only compile pre-v26 because the old event publishing
+//! helper used below is no longer available. If you are using v26 or later,
+//! use the updated implementation shown in the next code snippet.
 //!
-//! ```
+//! ```compile_fail
 //! use soroban_sdk::{Env, Address};
 //! use soroban_token_sdk::TokenUtils;
 //! // ... inside some token contract ...
@@ -27,7 +30,8 @@
 //!    from.require_auth();
 //!    // Token-specific implementation of balance movement.
 //!    token_impl::move_balance(&env, &from, &to, amount);
-//!    // Publish the event.
+//!    // Publish the event using the pre-v26 helper API.
+//!    // In v26+, use the event type from `soroban_token_sdk::events` instead.
 //!    TokenUtils::new(&env).events().transfer(from, to, amount);
 //! }
 //!

soroban-token-sdk/src/event.rs

@@ -2,11 +2,9 @@
 #![cfg_attr(feature = "docs", feature(doc_cfg))]
 pub mod _migrating;
 
-use crate::event::Events;
 use crate::metadata::Metadata;
 use soroban_sdk::Env;
 
-pub mod event;
 pub mod events;
 pub mod metadata;
 mod tests;
@@ -23,8 +21,4 @@ impl TokenUtils {
     pub fn metadata(&self) -> Metadata {
         Metadata::new(&self.0)
     }
-
-    pub fn events(&self) -> Events {
-        Events::new(&self.0)
-    }
 }