Ignore tenant not found error while increasing token usage. (#4950)

### What problem does this PR solve?

#4940

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/db/services/llm_service.py

@@ -173,7 +173,8 @@ class TenantLLMService(CommonService):
     def increase_usage(cls, tenant_id, llm_type, used_tokens, llm_name=None):
         e, tenant = TenantService.get_by_id(tenant_id)
         if not e:
-            raise LookupError("Tenant not found")
+            logging.error(f"Tenant not found: {tenant_id}")
+            return 0
 
         llm_map = {
             LLMType.EMBEDDING.value: tenant.embd_id,
@@ -186,7 +187,8 @@ class TenantLLMService(CommonService):
 
         mdlnm = llm_map.get(llm_type)
         if mdlnm is None:
-            raise ValueError("LLM type error")
+            logging.error(f"LLM type error: {llm_type}")
+            return 0
 
         llm_name, llm_factory = TenantLLMService.split_model_name_and_factory(mdlnm)