🗑️ Deprecate x86 (AMD64) Builds of GOV.UK Images

[dj-maisy]

User Need

As a Platform Engineer
I want to stop making x86 architecture builds of GOV.UK Application Images
so that we make our Build Pipelines more efficient and reliable

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What’s Needed

List anything the solution must do or be (behaviour, performance, security, UX, etc.).

• There is a "non" multi-architecture build action in govuk-infrastructure - make sure this is up to date with any improvements or modernisations
• Switch the Deploy/Release actions of the individual GOV.UK App Repos to use the updated build action.

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Acceptance Criteria

Clear, measurable conditions to verify the story is complete and valuable.

• Applications are building and deploying correctly
• Developers are notified of the change

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Assumptions (optional)

• The majority of Developers are on Apple Silicon MacBooks
• Any Developers still on Intel MacBooks can choose to build applications locally (but should strongly consider requesting a replacement device)

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Notes

This was previously suggested after the initial completion of the migration work from x86 to AWS Graviton. We spend more time in GitHub Runner Minutes producing x86 versions of our images that are likely almost never used and the multi-architecture build process has multiple stages including an extra "consolidation and manifest" stage at the end which only runs if all builds are successful.

This change has been resurfaced by a recent incident review relating to AWS Public ECR Repositories.

[jasonBirchall]

[pre-planning] we've decided it should be investigated (user research) before we carry out this work. This needs to go through refinement.

[nicholsj]

Suggestion is to wait until next dev laptop rollout to be finalised