Migrate CI from Travis to GitHub Actions (main branch)

[Copilot]

Targets main and migrates this plugin’s Travis-based CI to GitHub Actions with parity to the fully-resolved Travis matrix from logstash-plugins/.ci@1.x. The resolved config runs only the shared unit-test matrix on main, so this change adds only the unit-test workflow and retires Travis configuration.

• CI migration

  • Added .github/workflows/unit-tests.yml as the GHA consumer for logstash-plugins/.ci/.github/workflows/unit-tests.yml@1.x
  • Preserved the required trigger shape for main: push, pull_request, schedule, and workflow_dispatch
  • Added secrets: inherit on both callable jobs and explicit permissions: contents: read

• Travis → GHA parity

  Resolved Travis env	GHA coverage
  ELASTIC_STACK_VERSION=8.current DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack 8.current, snapshot: false
  ELASTIC_STACK_VERSION=9.previous DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack 9.previous, snapshot: false
  ELASTIC_STACK_VERSION=9.current DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack 9.current, snapshot: false
  SNAPSHOT=true ELASTIC_STACK_VERSION=8.current DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack 8.current, snapshot: true
  SNAPSHOT=true ELASTIC_STACK_VERSION=9.previous DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack 9.previous, snapshot: true
  SNAPSHOT=true ELASTIC_STACK_VERSION=9.current DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack 9.current, snapshot: true
  SNAPSHOT=true ELASTIC_STACK_VERSION=main DOCKER_ENV=dockerjdk21.env	Unit Tests reusable workflow, stack main, snapshot: true

  • No INTEGRATION=true entries in the resolved Travis config
  • No SECURE_INTEGRATION=true entries in the resolved Travis config
  • No enabled performance jobs (HAS_PERFORMANCE_TESTS=1 absent)
  • No local vendored .ci/ assets or Travis-provided service/env reconciliation required in this repo

• Repository cleanup

  • Replaced the Travis badge in README.md with the branch-scoped GitHub Actions unit-test badge
  • Deleted .travis.yml

• Workflow added

  • .github/workflows/unit-tests.yml

• Example

  jobs:
    tests:
      if: github.event_name != 'schedule'
      uses: logstash-plugins/.ci/.github/workflows/unit-tests.yml@1.x
      secrets: inherit
      with:
        timeout-minutes: 60