Fix wait_agent expectations in core tests (#14637)

## Summary
- update stale core tool-spec expectations from `wait` to `wait_agent`
- update the prompt-caching tool-name assertion to match the renamed
tool
- fix the Bazel regressions introduced after #14631 renamed the
multi-agent wait tool

## Testing
- cargo test -p codex-core tools::spec::tests
- cargo test -p codex-core
suite::prompt_caching::prompt_tools_are_consistent_across_requests

Co-authored-by: Codex <noreply@openai.com>

codex-rs/core/tests/suite/prompt_caching.rs

@@ -180,7 +180,7 @@ async fn prompt_tools_are_consistent_across_requests() -> anyhow::Result<()> {
         "spawn_agent",
         "send_input",
         "resume_agent",
-        "wait",
+        "wait_agent",
         "close_agent",
     ]);
     let body0 = req1.single_request().body_json();