bk: update junit-annotate to run faster

[Copilot]

Updates the Buildkite junit-annotate plugin configuration to run faster using containers instead of the GCP provider.

Changes Made

• Plugin Version: Updated from junit-annotate#v2.5.0 to junit-annotate#v2.7.0
• Agent Configuration: Replaced GCP provider with container image docker.elastic.co/ci-agent-images/buildkite-junit-annotate:1.0
• Performance Optimization: Added run-in-docker: false for improved execution speed
• Requirements: Added comment documenting that the container requires at least "bash", "curl" and "git"

The configuration change in .buildkite/pipeline.yml transforms the junit annotation step from:

- label: ":junit: Junit annotate"
  plugins:
    - junit-annotate#v2.5.0:
        artifacts: "**TEST-*.xml"
        always-annotate: true
  agents:
    provider: "gcp"

To:

- label: ":junit: Junit annotate"
  agents:
    # requires at least "bash", "curl" and "git"
    image: "docker.elastic.co/ci-agent-images/buildkite-junit-annotate:1.0"
  plugins:
    - junit-annotate#v2.7.0:
        artifacts: "**TEST-*.xml"
        always-annotate: true
        run-in-docker: false

This change maintains all existing functionality while providing faster execution by using a dedicated container image instead of provisioning GCP instances.

Fixes #10063.

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[mergify]

This pull request does not have a backport label. Could you fix it @Copilot? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-./d./d is the label that automatically backports to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[v1v]

@copilot this PR is WIP, finish the remaining work

[Copilot]

@copilot this PR is WIP, finish the remaining work

Completed the remaining work to update junit-annotate configuration. Updated .buildkite/pipeline.yml to use junit-annotate#v2.7.0 with container image docker.elastic.co/ci-agent-images/buildkite-junit-annotate:1.0 and run-in-docker: false for faster execution. Commit: 321a246

[fr4nc1sc0-r4m0n]

LGTM

[v1v]

buildkite test this

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 7d3a7a2

Failed CI Steps

• Unit tests - Windows 2022
• Win2022:sudo:install-uninstall
• x86_64:sudo: fleet

cc @v1v @Copilot