Enable parallel tool calls for all model prompts (#38499)

## What changed

- Set `parallel_tool_calls` for regular and remote compaction prompts without consulting model metadata.
- Remove `supports_parallel_tool_calls` from `ModelInfo`, the bundled model catalog, and related fixtures.
- Preserve the existing Responses Lite behavior that disables parallel tool calls at request construction.

GitOrigin-RevId: 49552bdf97e71fa57325abb49f8adc0c88f1401a

codex-rs/protocol/src/openai_models.rs

@@ -420,7 +420,6 @@ pub struct ModelInfo {
     #[serde(default)]
     pub web_search_tool_type: WebSearchToolType,
     pub truncation_policy: TruncationPolicyConfig,
-    pub supports_parallel_tool_calls: bool,
     #[serde(default)]
     pub supports_image_detail_original: bool,
     #[serde(default, skip_serializing_if = "Option::is_none")]
@@ -883,7 +882,6 @@ mod tests {
             apply_patch_tool_type: None,
             web_search_tool_type: WebSearchToolType::Text,
             truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-            supports_parallel_tool_calls: false,
             supports_image_detail_original: false,
             context_window: None,
             max_context_window: None,
@@ -1455,7 +1453,6 @@ mod tests {
                 "mode": "bytes",
                 "limit": 10000
             },
-            "supports_parallel_tool_calls": false,
             "supports_image_detail_original": false,
             "context_window": null,
             "auto_compact_token_limit": null,