Test hls-pragmas-plugin in ci

[jneira]

Dont know why it is not here 🤦

[Anton-Latukha]

This probably needs to be documented in the plugin cycle.

(checked - it is there).

[jneira]

yeah, it seems it was not added in #1833

another thing to document in the contributing guide (with that comprehensive check list) 😅

[Anton-Latukha]

Yes, it is there. But may be made more memorable.

Also this probably can be automatically checked in the CI.

For example - if there is a new folder in the plugins - the test workflow is required to be changed (implying to add the entry).

Since in the otherwise case - CI actually does not check that the plugin works properly.

[Anton-Latukha]

Opened #2531 for this.

[Anton-Latukha]

[skip circleci]

[jneira]

wow, tests passed, i was afraid they were bitrotten 😅