Initialize threadpools correctly during sysimg build (#55567)

I made a mistake with which threadpool was which.

(cherry picked from commit d5bbcc5)

Author: gbaraldi

src/init.c

@@ -884,8 +884,8 @@ static NOINLINE void _finish_julia_init(JL_IMAGE_SEARCH rel, jl_ptls_t ptls, jl_
         jl_n_markthreads = 0;
         jl_n_sweepthreads = 0;
         jl_n_gcthreads = 0;
-        jl_n_threads_per_pool[0] = 1;
-        jl_n_threads_per_pool[1] = 0;
+        jl_n_threads_per_pool[0] = 0; // Interactive threadpool
+        jl_n_threads_per_pool[1] = 1; // Default threadpool
     }
     jl_start_threads();