Tweak threading settings in colab

examples/pysr_demo.ipynb

@@ -772,7 +772,8 @@
         "the [Primes.jl](https://github.com/JuliaMath/Primes.jl) package.\n",
         "\n",
         "First, let's get the Julia backend\n",
-        "(here, we manually specify 4 threads and `-O3` - although this will only work if PySR has not yet started):"
+        "Here, we might choose to manually specify unlimited threads, `-O3`,\n",
+        "and `compile_modules=False`, although this will only propagate if Julia has not yet started:"
       ]
     },
     {
@@ -782,7 +783,9 @@
       "outputs": [],
       "source": [
         "import pysr\n",
-        "jl = pysr.julia_helpers.init_julia(julia_kwargs={\"threads\": 8, \"optimize\": 3})"
+        "jl = pysr.julia_helpers.init_julia(\n",
+        "    julia_kwargs={\"threads\": \"auto\", \"optimize\": 2, \"compiled_modules\": False}\n",
+        ")"
       ]
     },
     {