Super linter pipeline fixes and fixes to mysql template and airlock_processor.tf

[JC-wk]

Resolves #4846

What is being addressed

• Fix TFLINT errors in pipeline
• Fix for unused storage_mb param
• Fix duplicated tf var TOPIC_SUBSCRIPTION_NAME

2026-02-04 13:38:25 [INFO]   Command output for TERRAFORM_TFLINT:
------
1 issue(s) found:

Warning: Duplicate key: "TOPIC_SUBSCRIPTION_NAME", first defined at airlock_processor.tf:83,5-30 (terraform_map_duplicate_keys)

  on airlock_processor.tf line 99:
  99:     "TOPIC_SUBSCRIPTION_NAME"         = azurerm_servicebus_subscription.airlock_processor.name

Reference: https://github.com/terraform-linters/tflint-ruleset-terraform/blob/v0.13.0/docs/rules/terraform_map_duplicate_keys.md

1 issue(s) found:

Warning: [Fixable] variable "storage_mb" is declared but not used (terraform_unused_declarations)

  on variables.tf line 16:
  16: variable "storage_mb" {

How is this addressed

• Describe the changes made, and if appropriate, why they are addressed this way
• Note any pending work (with links to the issues that will address them)
• Update CHANGELOG.md
• Increment versions

[github-actions]

Unit Test Results

0 tests   0 ✅  0s ⏱️
0 suites  0 💤
0 files    0 ❌

Results for commit 820bf88.

♻️ This comment has been updated with latest results.

[marrobi]

/test-extended

(given airlock subscription change_

[github-actions]

🤖 pr-bot 🤖

🏃 Running extended tests: https://github.com/microsoft/AzureTRE/actions/runs/21706311183 (with refid 2fb76d34)

(in response to this comment from @marrobi)

[marrobi]

/test-force-approve

Failing on #1054 on delete.

[github-actions]

🤖 pr-bot 🤖

✅ Marking tests as complete (for commit 820bf88)

(in response to this comment from @marrobi)