feat: Add `disable_module_cache` attribute to `coderd_template` resource

[blinkagent]

Summary

The coderd_template resource does not currently expose the disable_module_cache attribute, which was added to the Coder API in coder/coder#21931 (v2.31+). This means templates managed via Terraform have no way to control this setting.

Context

Since v2.30 (coder/coder#21398), Terraform modules are cached at template import time and reused for all subsequent workspace builds. A per-template toggle disable_module_cache was added in coder/coder#21931 to allow opting out of this behavior.

The setting is available via:

• The Coder UI (Template Settings)
• The REST API (PATCH /api/v2/templates/{id} with disable_module_cache: true)

But it is not available via the coderd_template Terraform resource, which is the primary way many teams manage their templates as code.

Related

• bug: Terraform module caching silently overrides semver version constraints, no deployment-level opt-out coder#22834 — Tracks the broader gaps: deployment-level flag, TF provider support, v2.30 backport
• bug: Terraform module clone from Git repo no longer allows for relative-path file inclusion coder#22531 — Related bug where module caching breaks relative-path file inclusion

API Reference

The Coder SDK already supports this field:

• codersdk.UpdateTemplateMeta.DisableModuleCache (*bool, JSON: disable_module_cache)
• Endpoint: PATCH /api/v2/templates/{id}

Proposed Change

Add a disable_module_cache boolean attribute to the TemplateResourceModel struct in internal/provider/template_resource.go, following the same pattern as the recently added cors_behavior (#293) and use_classic_parameter_flow attributes.

Default should be false (caching enabled) to match the server-side default.

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Filed on behalf of @bjornrobertsson