fix: retain types on worker commands items

Added missing toYaml to command args template.

Example output before the fix:

command:
- npm
- run
- start
- --
- -workerId
- 1

This resulted in Kubernetes invalidating the chart as 1 is interpreted as a number instead of a string.
After the fix:

command:
- npm
- run
- start
- --
- -workerId
- "1"

Using toYaml ensures the original type from values is retained in the YAML output.

This is my first contribution to this project, and to GitLab as a whole. I also added a test case for this scenario but I'm not very competent in Go. I'm open to your feedback :)