Migrate CI from Travis to GitHub Actions (main branch)

[Copilot]

This PR migrates CI for the main branch from Travis to GitHub Actions while preserving Travis test coverage parity. It replaces Travis configuration with a reusable GHA unit-test workflow and updates repository status badges accordingly.

• Scope / branch

  • Targets main only (default branch migration path).

• Workflow migration

  • Added: .github/workflows/unit-tests.yml
  • Uses reusable workflow: logstash-plugins/.ci/.github/workflows/unit-tests.yml@1.x
  • Includes required trigger shape (push, pull_request, schedule, workflow_dispatch), scheduled branch fanout (branch: [main]), secrets: inherit, and timeout-minutes: 60.
  • Added explicit token permissions:

    permissions:
      contents: read

• Resolved Travis → GHA parity map

  • Resolved .travis.yml imports: travis/defaults.yml, travis/matrix.yml, travis/exec.yml from .ci@1.x.
  • Travis effective matrix entries mapped to GHA Unit Tests job matrix:

  Travis env combination	GHA coverage
  ELASTIC_STACK_VERSION=9.current DOCKER_ENV=dockerjdk21.env	unit-tests.yml → reusable unit-tests matrix
  ELASTIC_STACK_VERSION=9.previous DOCKER_ENV=dockerjdk21.env	same
  ELASTIC_STACK_VERSION=8.current DOCKER_ENV=dockerjdk21.env	same
  SNAPSHOT=true ELASTIC_STACK_VERSION=main DOCKER_ENV=dockerjdk21.env	same
  SNAPSHOT=true ELASTIC_STACK_VERSION=9.current DOCKER_ENV=dockerjdk21.env	same
  SNAPSHOT=true ELASTIC_STACK_VERSION=9.previous DOCKER_ENV=dockerjdk21.env	same
  SNAPSHOT=true ELASTIC_STACK_VERSION=8.current DOCKER_ENV=dockerjdk21.env	same

  • No resolved INTEGRATION=true or SECURE_INTEGRATION=true entries; no plugin-local performance trigger (HAS_PERFORMANCE_TESTS=1). Therefore no integration/secure/performance workflows were added.

• Travis env variable reconciliation

  • Variables introduced by resolved Travis matrix: ELASTIC_STACK_VERSION, DOCKER_ENV, SNAPSHOT.
  • These are re-derived by the reusable workflow/setup path.
  • Vendored .ci/ references only JRUBY_OPTS; no Travis-only variable dependency requiring workflow env injection.

• CI harness / vendored .ci/

  • Reviewed .ci/ (.ci/run.sh only).
  • No stale docker-compose v1 invocations and no vendored file changes required.

• README badge migration

  • Replaced Travis badge with GitHub Actions Unit Tests badge for main:

    [![Unit Tests](https://github.com/logstash-plugins/logstash-input-jms/actions/workflows/unit-tests.yml/badge.svg?branch=main)](https://github.com/logstash-plugins/logstash-input-jms/actions/workflows/unit-tests.yml)

• Travis removal

  • Deleted .travis.yml.

[donoghuc]

/pr_prepare release:patch

• Fix NameError: uninitialized constant Fixnum when reading a JMS MapMessage on Logstash 9.4+
  • The jruby-jms gem references the Fixnum constant, which Ruby removed in 3.2 (shipped by the JRuby in Logstash 9.4+). This raised a NameError while decoding a JMS MapMessage. Alias the removed Fixnum/Bignum constants to Integer before requiring jms.