Error: `add-path`/`set-path` commands are deprecated

[MatheusRich]

Log:

Run justgook/setup-elm@1.2.0
Trying to restore cached ELM config
ENOENT: no such file or directory, open './elm.json'
Cache Size: ~6 MB (6220294 B)
/bin/tar --use-compress-program zstd -d -xf /home/runner/work/_temp/50e33d56-ac73-4e98-8154-3c43d052f013/cache.tzst -P -C /home/runner/work/tcc-implementations/tcc-implementations
Error: Unable to process command '::add-path::/home/runner/elm_home/' successfully.
Error: The `add-path` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
Error: Unable to process command '::set-env name=ELM_HOME::/home/runner/elm_home' successfully.
Error: The `set-env` command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the `ACTIONS_ALLOW_UNSECURE_COMMANDS` environment variable to `true`. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/

More info: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/

[ben181231]

I also faced a similar issue.