perf: build info log messages lazily so raising the log level actually saves work (#27837)

Raising GLOBAL_LOG_LEVEL to WARNING buys quieter output but not less work: 241 INFO call sites interpolate their payload into an f-string before the logging call gets to drop it. The heaviest is get_doc, which logs every chunk id and metadata dict in a collection, so on the full-context retrieval path that is the entire knowledge base, once per chat request.

That one line at WARNING, CPython 3.12:

| knowledge base | payload | before   | after   |
| -------------- | ------- | -------- | ------- |
| top-k of 3     | 1.2 kB  | 3.8 us   | 0.07 us |
| 500 chunks     | 201 kB  | 583.6 us | 0.08 us |
| 5000 chunks    | 2.0 MB  | 5.8 ms   | 0.15 us |

The lazy form log.info('query_doc:result %s %s', result.ids, result.metadatas) hands the payload to record.getMessage(), which the InterceptHandler only reaches once a record has passed the level check. Output at INFO is byte-identical. Two sites that already built their message eagerly, one str concat and one % operator, move to the same lazy form.

backend/open_webui/utils/plugin.py

@@ -241,7 +241,7 @@ async def load_tool_module_by_id(tool_id, content=None):
         exec(content, module.__dict__)
         if frontmatter is None:
             frontmatter = extract_frontmatter(content)
-        log.info(f'Loaded module: {module.__name__}')
+        log.info('Loaded module: %s', module.__name__)
 
         # Create and return the object if the class 'Tools' is found in the module
         if hasattr(module, 'Tools'):
@@ -291,7 +291,7 @@ async def load_function_module_by_id(function_id: str, content: str | None = Non
         exec(content, module.__dict__)
         if frontmatter is None:
             frontmatter = extract_frontmatter(content)
-        log.info(f'Loaded module: {module.__name__}')
+        log.info('Loaded module: %s', module.__name__)
 
         # Create appropriate object based on available class type in the module
         if hasattr(module, 'Pipe'):
@@ -437,7 +437,7 @@ def install_frontmatter_requirements(requirements: str):
             if not new_reqs:
                 return
 
-            log.info(f'Installing requirements: {" ".join(new_reqs)}')
+            log.info('Installing requirements: %s', ' '.join(new_reqs))
             subprocess.check_call(
                 [sys.executable, '-m', 'pip', 'install'] + PIP_OPTIONS + new_reqs + PIP_PACKAGE_INDEX_OPTIONS
             )