ci: update GitHub workflows and improve test configurations

- Update golangci-lint-action from v4 to v6 in GitHub workflow

Signed-off-by: appleboy <[email protected]>

chore: refactor release process configuration

- Change the changelog configuration in `.goreleaser.yaml` from using GitHub to using git.

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

refactor: remove unnecessary line setting FilePath field to .host

- Remove the line that sets the `FilePath` field to `.host`

Signed-off-by: appleboy <[email protected]>

feat: update plugin functionality in main.go and plugin.go files

- Add a new flag to the main.go file
- Add a new field to the Plugin type in the plugin.go file
- Remove two lines from the plugin_test.go file

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

chore: update external dependencies to latest versions

- Update the version of `github.com/appleboy/easyssh-proxy` from `v1.4.1-0.20231106031702-5666e2ea5156` to `v1.5.0`
- Update the version of `github.com/urfave/cli/v2` from `v2.26.0` to `v2.27.1`

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

chore: update dependencies to latest versions

- Update `github.com/urfave/cli` dependency from `v2.25.7` to `v2.26.0`
- Upgrade `golang.org/x/crypto` from `v0.14.0` to `v0.17.0`
- Bump `github.com/cpuguy83/go-md2man` from `v2.0.2` to `v2.0.3`
- Update `github.com/xrash/smetrics` to a newer commit
- Update `golang.org/x/sys` from `v0.14.0` to `v0.15.0`

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

feat: implement and test all environment variables functionality (#264)

- Add a new flag `allenvs` to pass all environment variables to the shell script
- Implement the `AllEnvs` functionality in the `exec` function
- Add a new function `findEnvs` to find all environment variables with specified prefixes
- Add tests for the `findEnvs` function and the `AllEnvs` functionality

ci: improve release process and test robustness

- Add extra_files with .xz glob pattern to .goreleaser.yaml

Signed-off-by: appleboy <[email protected]>

docs: improve clarity of `Usage` message in main.go

- Modify the `Usage` message in main.go

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

feat: refactor code for parallel execution on multiple hosts (#249)

- Add `trimValues` function for cleaning up slice values
- Remove unused `wg.Done()` call
- Modify `Exec` function to launch goroutines for each host in `Config.Host`
- Add test for `ScriptStop` with multiple hosts and sync mode

refer to: appleboy/ssh-action#233