Ability to control if pipelines get created via params in inputs.yml file

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Infrastructure as Code Type? (Required)

both

### Starter Module? (Required)

terraform - platform_landing_zone

### Use Case (Required)

**Use Case**

Currently, the module supports various parameters in the inputs.yml file that control how code generation and pipeline setup are handled, as described in the [Azure Landing Zone Terraform Accelerator user guide](https://azure.github.io/Azure-Landing-Zones/accelerator/userguide/2_start/terraform-azuredevops/)
.

However, there is no parameter to disable pipeline creation.

In scenarios where organizations use Terraform Cloud for CI/CD, the generated Azure DevOps or GitHub pipelines are unnecessary and must be manually deleted after bootstrap. This adds friction to the setup process and can lead to inconsistent environments.

**Feature Request**

Add a new parameter (e.g., createPipelines: true|false) in the inputs.yml configuration file.

When set to false, the bootstrap process should skip pipeline creation while still generating all other artifacts as usual.

**Benefits**

- Simplifies setup for teams using external CI/CD (e.g., Terraform Cloud).-
- Reduces cleanup overhead after bootstrap.-
- Provides finer control and flexibility for customers adopting hybrid deployment workflows.

### Proposed Solution (Required)

Introduce a new boolean parameter in the inputs.yml file, for example:

`createPipelines: true`

When set to false, the bootstrap process should skip generating any Azure DevOps or GitHub pipeline YAML files while still creating all other necessary artifacts (e.g., configuration files, environment setup).

This change would align with scenarios where CI/CD is already managed externally (e.g., Terraform Cloud), providing users with finer control over what gets generated and reducing post-deployment cleanup.

### Important Factoids (Optional)

_No response_

### References (Optional)

_No response_

The payload names inputs.yml and the terraform/platform_landing_zone starter module; begin by tracing how that configuration reaches bootstrap artifact generation. Check the existing Azure DevOps and GitHub pipeline generation paths, then verify that false omits those pipeline files while other artifacts still appear.

Written by the indexing model from the issue text.