Removing IREE_API_VERSION. (#10937)

It's unused and will never really do anything in the future.
diff --git a/samples/static_library/static_library_demo.c b/samples/static_library/static_library_demo.c
index ceb9770..04ae282 100644
--- a/samples/static_library/static_library_demo.c
+++ b/samples/static_library/static_library_demo.c
@@ -66,8 +66,7 @@
 
   // Instance configuration (this should be shared across sessions).
   iree_runtime_instance_options_t instance_options;
-  iree_runtime_instance_options_initialize(IREE_API_VERSION_LATEST,
-                                           &instance_options);
+  iree_runtime_instance_options_initialize(&instance_options);
   iree_runtime_instance_options_use_all_available_drivers(&instance_options);
   iree_runtime_instance_t* instance = NULL;