remove fake slither tool

src/agents/auditor/tools/slither-tool.ts

@@ -1,15 +0,0 @@
-import { tool } from "langchain";
-import { z } from "zod";
-
-export const slitherTool = tool(
-  async (_input) => {
-    return [];
-  },
-  {
-    name: "slither",
-    description: "Run slither static analysis on a Solidity contract.",
-    schema: z.object({
-      solidityFile: z.string().describe("The Solidity source code to analyze."),
-    }),
-  },
-);