Temporarily remove SD 1.5 from Runway

Remove unavailable checkpoints that is bugging the CI of Optimum Neuron.

inference-cache-config/stable-diffusion.json

@@ -1,8 +1,4 @@
 {
-    "runwayml/stable-diffusion-v1-5": [
-        {  "task": "stable-diffusion", "batch_size": 1, "height": 512, "width": 512, "num_images_per_prompt": 1, "auto_cast": "matmul", "auto_cast_type": "bf16" },
-        {  "task": "stable-diffusion", "batch_size": 1, "height": 768, "width": 768, "num_images_per_prompt": 1, "auto_cast": "matmul", "auto_cast_type": "bf16" }
-    ],
     "stabilityai/stable-diffusion-2-1": [
         {  "task": "stable-diffusion", "batch_size": 1, "height": 512, "width": 512, "num_images_per_prompt": 1, "auto_cast": "matmul", "auto_cast_type": "bf16" },
         {  "task": "stable-diffusion", "batch_size": 1, "height": 768, "width": 768, "num_images_per_prompt": 1, "auto_cast": "matmul", "auto_cast_type": "bf16" }