UML-3146 Disable apply shared TF in PR workflow

[ntse]

Purpose

Prevent other pull requests from overwriting changes to Terraform shared / account

Fixes UML-3146

Approach

Disable applying the Terraform shared / account during the PR workflow and do only a plan. Also, temporarily disabled in (Pre-)production to allow this PR to be merged.

Learning

Any tips and tricks, blog posts or tools which helped you. Plus anything notable you've discovered about the Use a Lasting Power of Attorney service

Checklist

• I have performed a self-review of my own code
• I have added relevant logging with appropriate levels to my code
• New event_codes have been documented on the wiki page
• I have updated documentation (Confluence/GitHub wiki/tech debt doc) where relevant
• I have added tests to prove my work
• I have added welsh translation tags and updated translation files
• I have run an accessibility tool on any pages I have made changes to and fixed any issues found
• I have notified the Interaction Designer of any content changes so that appropriate screenshots/flow diagram changes can be made
• The product team have tested these changes