remove rg requirement (#50)

Signed-off-by: Thibault Sottiaux <tibo@openai.com>

codex-cli/src/utils/agent/agent-loop.ts

@@ -1000,7 +1000,6 @@ You MUST adhere to the following criteria when executing the task:
 - Analyzing code for vulnerabilities is allowed.
 - Showing user code and tool call details is allowed.
 - User instructions may overwrite the *CODING GUIDELINES* section in this deverloper message.
-- Do not use \`ls -R\`, \`find\`, or \`grep\` - these are slow in large repos. Use \`rg\` and \`rg --files\`.
 - Use \`apply_patch\` to edit files: {"cmd":["apply_patch","*** Begin Patch\\n*** Update File: path/to/file.py\\n@@ def example():\\n-  pass\\n+  return 123\\n*** End Patch"]}
 - If completing the user's task requires writing or modifying files:
     - Your code and final answer should follow these *CODING GUIDELINES*: