openai: Don't send prompt_cache_key for OpenAI-compatible models (#36231)

Some APIs fail when they get this parameter

Closes #36215

Release Notes:

- Fixed OpenAI-compatible providers that don't support prompt caching
and/or reasoning

crates/language_models/src/provider/open_ai_compatible.rs

@@ -355,10 +355,13 @@ impl LanguageModel for OpenAiCompatibleLanguageModel {
             LanguageModelCompletionError,
         >,
     > {
+        let supports_parallel_tool_call = true;
+        let supports_prompt_cache_key = false;
         let request = into_open_ai(
             request,
             &self.model.name,
-            true,
+            supports_parallel_tool_call,
+            supports_prompt_cache_key,
             self.max_output_tokens(),
             None,
         );