[Inference] LoRA: use the precomputed adapterWeightsPath property (#1379)

Following @Wauplin 's comment
[here](huggingface/huggingface_hub#3005 (comment))

Pre-requisite: merge and deploy [this internal PR
first](huggingface-internal/moon-landing#13498)

Author: SBrandeis

packages/inference/src/lib/getInferenceProviderMapping.ts

@@ -8,7 +8,7 @@ import { typedInclude } from "../utils/typedInclude";
 export const inferenceProviderMappingCache = new Map<ModelId, InferenceProviderMapping>();
 
 export type InferenceProviderMapping = Partial<
-	Record<InferenceProvider, Omit<InferenceProviderModelMapping, "hfModelId" | "adapterWeightsPath">>
+	Record<InferenceProvider, Omit<InferenceProviderModelMapping, "hfModelId">>
 >;
 
 export interface InferenceProviderModelMapping {
@@ -74,22 +74,6 @@ export async function getInferenceProviderMapping(
 				`Model ${params.modelId} is in staging mode for provider ${params.provider}. Meant for test purposes only.`
 			);
 		}
-		if (providerMapping.adapter === "lora") {
-			const treeResp = await (options?.fetch ?? fetch)(`${HF_HUB_URL}/api/models/${params.modelId}/tree/main`);
-			if (!treeResp.ok) {
-				throw new Error(`Unable to fetch the model tree for ${params.modelId}.`);
-			}
-			const tree: Array<{ type: "file" | "directory"; path: string }> = await treeResp.json();
-			const adapterWeightsPath = tree.find(({ type, path }) => type === "file" && path.endsWith(".safetensors"))?.path;
-			if (!adapterWeightsPath) {
-				throw new Error(`No .safetensors file found in the model tree for ${params.modelId}.`);
-			}
-			return {
-				...providerMapping,
-				hfModelId: params.modelId,
-				adapterWeightsPath,
-			};
-		}
 		return { ...providerMapping, hfModelId: params.modelId };
 	}
 	return null;

packages/inference/src/providers/fal-ai.ts

@@ -86,16 +86,6 @@ export class FalAITextToImageTask extends FalAITask implements TextToImageTaskHe
 			...(params.args.parameters as Record<string, unknown>),
 			sync_mode: true,
 			prompt: params.args.inputs,
-			...(params.mapping?.adapter === "lora" && params.mapping.adapterWeightsPath
-				? {
-						loras: [
-							{
-								path: buildLoraPath(params.mapping.hfModelId, params.mapping.adapterWeightsPath),
-								scale: 1,
-							},
-						],
-				  }
-				: undefined),
 		};
 
 		if (params.mapping?.adapter === "lora" && params.mapping.adapterWeightsPath) {