Change simulation examples from github actions to gitlab pipelines

[VigneshVSV]

Currently the docker images are being built in github (as the project was originally created in github). A copy of these repositories are available in gitlab (see link in project README or within the gitsubmodule). Change the jobs from github to gitlab CI syntax.

Affected submodules

• oscilloscope simulator (https://gitlab.com/hololinked/examples/servers/oscilloscope-simulator)
• spectrometer simulator (https://gitlab.com/hololinked/examples/servers/spectrometer-simulator)
• for camera simulator, add a new job (no job exists) (https://gitlab.com/hololinked/examples/servers/simulations/camera-simulator)