refactor: refactor signal handling and update build tags

- Refactor signal handling tests in `manager_test.go` to use a new `testingSignal` helper function
- Update build tags in `signals_unix.go` to exclude Windows systems

Signed-off-by: Bo-Yi Wu <[email protected]>

refactor(signal): refactor signal handling across platforms (#17)

- Refactor signal handling in `manager.go` to use a slice of signals instead of individual signal constants.
- Remove handling of `SIGTSTP` signal and associated logging in `manager.go`.
- Update signal sending in tests within `manager_test.go` to use `os.FindProcess` and `process.Signal` instead of `syscall.Kill`.
- Add `os` package import in `manager_test.go`.
- Create new file `signals_unix.go` with a slice of signals for Unix-based systems including `SIGINT`, `SIGTERM`, and `SIGTSTP`.
- Create new file `signals_windows.go` with a slice of signals for Windows systems including `SIGINT` and `SIGTERM`.

Signed-off-by: Bo-Yi Wu <[email protected]>

ci: refactor GitHub Actions workflows

- Update GitHub Actions checkout to version 4 in codeql.yaml, go.yml, and goreleaser.yml workflows
- Update GitHub Actions CodeQL init and analyze to version 3 in codeql.yaml workflow
- Add checkout step with fetch-depth 0 in go.yml workflow
- Remove specific go-version in favor of go.mod versioning in go.yml and goreleaser.yml workflows
- Enable check-latest for Go version in go.yml and goreleaser.yml workflows
- Update GitHub Actions golangci-lint to version 4 in go.yml workflow
- Add Go version 1.22 to the test matrix in go.yml workflow
- Update GitHub Actions cache to version 4 in go.yml workflow
- Update GitHub Actions codecov to version 4 in go.yml workflow
- Update GitHub Actions goreleaser to version 5 in goreleaser.yml workflow
- Change goreleaser action argument from `--rm-dist` to `--clean` in goreleaser.yml workflow

Signed-off-by: Bo-Yi Wu <[email protected]>

chore: refactor changelog generation and sorting

- Add a new file `.goreleaser.yaml`
- Set `project_name` to `graceful`
- Skip the build process
- Include the changelog generation
- Use `git` as the implementation for changelog generation
- Sort the changelog in ascending order
- Group commits messages into different categories
- Apply filters to exclude certain commit messages from the changelog

Signed-off-by: Bo-Yi Wu <[email protected]>

chore(context): get shutdown context

Signed-off-by: Bo-Yi Wu <[email protected]>

fix: set another variable.

Signed-off-by: Bo-Yi Wu <[email protected]>

chore(manager): update runAtShutdown

Signed-off-by: Bo-Yi Wu <[email protected]>

docs: add codecov badge

Signed-off-by: Bo-Yi Wu <[email protected]>