Upgrade to gitlab-fog-azure-rm v1.8.0

What does this MR do and why?

This pulls in gitlab-org/ruby/gems/gitlab-fog-azure-rm!39 (merged) to drop the dependency on the archived ms_rest_azure gem. As a result, this removes one dependency on Faraday v1.

Relates to #408884 (closed)

How to set up and validate locally

1. Get an Azure storage account and bucket set up.
2. In gdk.yml:

object_store:
  connection:
    provider: AzureRM
    azure_storage_account_name: <STORAGENAME>
    azure_storage_access_key: <STORAGE KEY>
  consolidated_form: true
  enabled: true
  objects:
    artifacts:
      bucket: test1/artifacts
    external_diffs:
      bucket: test1/external_diffs
    lfs:
      bucket: test1/lfs
    uploads:
      bucket: test1/uploads
    packages:
      bucket: test1/packages
    dependency_proxy:
      bucket: test1/dependency-proxy
    terraform_state:
      bucket: test1/terraform
    pages:
      bucket: test1/pages
    ci_secure_files:
      bucket: test1/ci_secure_files

3. gdk restart rails
4. Try to upload an attachment.

MR acceptance checklist

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