Run tests with arm64 architecture

[friedrichg]

Is your feature request related to a problem? Please describe.
With arm64 image being used in production in many locations,
we should run integrations tests for it

Describe the solution you'd like
Run same tests we run with amd64 with arm64 architecture in github actions

[danielblando]

I think we can do something like

integration-configs-db:
  needs: build
  strategy:
    matrix:
      os: [ubuntu-24.04, ubuntu-24.04-arm64]
  runs-on: ${{ matrix.os }}
  steps:

Use a matrix and have multiple runs-on on https://github.com/cortexproject/cortex/blob/master/.github/workflows/test-build-deploy.yml

[thc1006]

Update on PR #7068:

The PR has been rebased onto the latest master branch (as of 2025-11-01), which includes several important upstream fixes including PR #7082 (visit marker race condition fix).

Current implementation status:

• Matrix strategy for running 8 integration test suites on both amd64 and arm64
• Architecture-aware Docker image selection
• Fixed install-docker.sh to support ARM64 architecture detection
• 5 of 8 test suites passing on ARM64 (requires_docker, integration_alertmanager, integration_memberlist, integration_ruler, integration_remote_write_v2)

Three test suites are skipped on ARM64 with documented reasons:

• integration_backward_compatibility: Old Cortex versions (v1.13.1-v1.14.0) lack ARM64 images
• integration_query_fuzz: Architecture-specific floating-point arithmetic differences
• integration_querier: Timing-sensitive cache request count variations

The PR also includes a cleanup commit removing deprecated // +build tags from 40 files to resolve linter warnings with newer golangci-lint versions.

All core ARM64 functionality has been verified locally with lint passing (0 issues). The implementation is backward compatible and introduces no additional costs as GitHub provides free ARM64 runners for public repositories.

The PR is ready for review and awaiting CI approval.