Replace unmaintained gopkg.in/op/go-logging.v1 with log/slog

[alexandear]

Please describe your feature request.

yq depends on gopkg.in/op/go-logging.v1, which has been unmaintained for 10 years.

Describe the solution you'd like

I propose replacing it with the standard library log/slog package introduced to modernize logging and remove the external dependency.

Describe alternatives you've considered

• Switching to another third party logger
• Keeping current dependency