feat(coder-labs/modules/codex): bump agentapi version to v0.11.8 in codex (#727)

## Description
- bump agentapi version to v0.11.8 in codex

## Type of Change

- [ ] New module
- [ ] New template
- [ ] Bug fix
- [x] Feature/enhancement
- [ ] Documentation
- [ ] Other

## Module Information

<!-- Delete this section if not applicable -->

**Path:** `registry/coder-labs/modules/codex`  
**New version:** `v4.1.1`  
**Breaking change:** [ ] Yes [x] No

## Testing & Validation

- [x] Tests pass (`bun test`)
- [x] Code formatted (`bun fmt`)
- [x] Changes tested locally

## Related Issues

<!-- Link related issues or write "None" if not applicable -->

registry/coder-labs/modules/codex/README.md

@@ -13,7 +13,7 @@ Run Codex CLI in your workspace to access OpenAI's models through the Codex inte
 ```tf
 module "codex" {
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "4.1.0"
+  version        = "4.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = var.openai_api_key
   workdir        = "/home/coder/project"
@@ -32,7 +32,7 @@ module "codex" {
 module "codex" {
   count          = data.coder_workspace.me.start_count
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "4.1.0"
+  version        = "4.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = "..."
   workdir        = "/home/coder/project"
@@ -51,7 +51,7 @@ For tasks integration with AI Bridge, add `enable_aibridge = true` to the [Usage
 ```tf
 module "codex" {
   source          = "registry.coder.com/coder-labs/codex/coder"
-  version         = "4.1.0"
+  version         = "4.1.1"
   agent_id        = coder_agent.example.id
   workdir         = "/home/coder/project"
   enable_aibridge = true
@@ -94,7 +94,7 @@ data "coder_task" "me" {}
 
 module "codex" {
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "4.1.0"
+  version        = "4.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = "..."
   ai_prompt      = data.coder_task.me.prompt
@@ -112,7 +112,7 @@ This example shows additional configuration options for custom models, MCP serve
 ```tf
 module "codex" {
   source         = "registry.coder.com/coder-labs/codex/coder"
-  version        = "4.1.0"
+  version        = "4.1.1"
   agent_id       = coder_agent.example.id
   openai_api_key = "..."
   workdir        = "/home/coder/project"

registry/coder-labs/modules/codex/main.tf

@@ -131,7 +131,7 @@ variable "install_agentapi" {
 variable "agentapi_version" {
   type        = string
   description = "The version of AgentAPI to install."
-  default     = "v0.11.6"
+  default     = "v0.11.8"
 }
 
 variable "codex_model" {