feat(cli): promote tasks commands from experimental to GA (#20916)

## Overview

This change promotes the tasks CLI commands from `coder exp task` to
`coder task`, marking them as generally available (GA).

## Migration

Users will need to update their scripts from:

```shell
coder exp task create "my task"
```

To:
```shell
coder task create "my task"
```

---

🤖 This change was written by Claude Sonnet 4.5 Thinking using [mux](https://github.com/coder/mux) and reviewed by a human 🏄🏻‍♂️

docs/reference/cli/task_delete.md

@@ -0,0 +1,40 @@
+<!-- DO NOT EDIT | GENERATED CONTENT -->
+# task delete
+
+Delete tasks
+
+Aliases:
+
+* rm
+
+## Usage
+
+```console
+coder task delete [flags] <task> [<task> ...]
+```
+
+## Description
+
+```console
+  - Delete a single task.:
+
+     $ $ coder task delete task1
+
+  - Delete multiple tasks.:
+
+     $ $ coder task delete task1 task2 task3
+
+  - Delete a task without confirmation.:
+
+     $ $ coder task delete task4 --yes
+```
+
+## Options
+
+### -y, --yes
+
+|      |                   |
+|------|-------------------|
+| Type | <code>bool</code> |
+
+Bypass prompts.