Remove toolcache decorator

This decorator enabled us to use the functionality of the Actions
toolcache within the runner too.
Now that we've deleted the runner we no longer need it.

src/runner.ts

@@ -1,5 +1,4 @@
 import * as fs from "fs";
-import * as os from "os";
 import * as path from "path";
 
 import { Command } from "commander";
@@ -47,14 +46,6 @@ function getTempDir(userInput: string | undefined): string {
   return tempDir;
 }
 
-function getToolsDir(userInput: string | undefined): string {
-  const toolsDir = userInput || path.join(os.homedir(), "codeql-runner-tools");
-  if (!fs.existsSync(toolsDir)) {
-    fs.mkdirSync(toolsDir, { recursive: true });
-  }
-  return toolsDir;
-}
-
 const codeqlEnvJsonFilename = "codeql-env.json";
 
 function loadTracerEnvironment(config: Config): { [name: string]: string } {
@@ -194,7 +185,6 @@ program
 
     try {
       const tempDir = getTempDir(cmd.tempDir);
-      const toolsDir = getToolsDir(cmd.toolsDir);
       const checkoutPath = cmd.checkoutPath || process.cwd();
 
       // Wipe the temp dir
@@ -237,7 +227,6 @@ program
             undefined,
             apiDetails,
             tempDir,
-            toolsDir,
             gitHubVersion.type,
             logger
           )
@@ -256,7 +245,6 @@ program
         "",
         parseRepositoryNwo(cmd.repository),
         tempDir,
-        toolsDir,
         codeql,
         workspacePath,
         gitHubVersion,