enable chat_template.jinja to fix transformers upgrade (#3583)

Author: dtrawins

demos/common/export_models/requirements.txt

@@ -2,14 +2,14 @@
 --extra-index-url "https://storage.openvinotoolkit.org/simple/wheels/nightly"
 --extra-index-url "https://storage.openvinotoolkit.org/simple/wheels/pre-release"
 --pre
-optimum-intel
+optimum-intel@git+https://github.com/huggingface/optimum-intel.git
 openvino-tokenizers<=2025.3.0.0.dev20250812
 openvino<=2025.3.0.dev20250814
 nncf>=2.11.0 
 sentence_transformers
 sentencepiece==0.2.0
 openai 
-transformers<4.53
+transformers<4.54
 einops
 torchvision
 timm==1.0.15

src/llm/servable_initializer.cpp

@@ -137,13 +137,16 @@ void GenAiServableInitializer::loadPyTemplateProcessor(std::shared_ptr<GenAiServ
             tool_template = None
 
             # Try to read template from template.jinja file
-            jinja_file = Path(templates_directory + "/template.jinja")
+            jinja_file = Path(templates_directory + "/chat_template.jinja")
+            jinja_file_legacy = Path(templates_directory + "/template.jinja")
             template_loader = jinja2.FileSystemLoader(searchpath=templates_directory)
             jinja_env = ImmutableSandboxedEnvironment(trim_blocks=True, lstrip_blocks=True, extensions=[AssistantTracker, jinja2.ext.loopcontrols], loader=template_loader)
             jinja_env.policies["json.dumps_kwargs"]["ensure_ascii"] = False
             jinja_env.globals["raise_exception"] = raise_exception
             jinja_env.globals["strftime_now"] = strftime_now
             if jinja_file.is_file():
+                template = jinja_env.get_template("chat_template.jinja")
+            elif jinja_file_legacy.is_file():
                 template = jinja_env.get_template("template.jinja")
 
             # Try to read data from tokenizer_config.json

src/test/llm/llmtemplate_test.cpp

@@ -725,7 +725,7 @@ class LLMChatTemplateHttpTest : public TestWithTempDir {
         ON_CALL(*writer, PartialReplyBegin(::testing::_)).WillByDefault(testing::Invoke([](std::function<void()> fn) { fn(); }));
         TestWithTempDir::SetUp();
         tokenizerConfigFilePath = directoryPath + "/tokenizer_config.json";
-        jinjaConfigFilePath = directoryPath + "/template.jinja";
+        jinjaConfigFilePath = directoryPath + "/chat_template.jinja";
         ovmsConfigFilePath = directoryPath + "/ovms_config.json";
         graphConfigFilePath = directoryPath + "/graph_config.pbtxt";