ci: add GitHub Actions workflow for tests and linting

[HackStrix]

This pull request adds a new GitHub Actions workflow for continuous integration (CI) to the project. The workflow automates testing and linting for Go code on pushes and pull requests to the main branch.

CI workflow additions:

• Introduced a .github/workflows/ci.yml file that sets up two jobs: one for running tests (across Go versions 1.21.x and 1.22.x) and one for linting the codebase using golangci-lint.
• The test job checks out the code, sets up the appropriate Go version, verifies dependencies, builds the project, and runs tests with race detection and coverage reporting.
• The lint job checks out the code, sets up Go 1.21.x, and runs golangci-lint with a 5-minute timeout to enforce code quality.