Autobuild: Minimize JSON-RPC workflow permissions

[ann0see]

Short description of changes
Removes any permissions from JSON-RPC check. We might even drop the secret in the env fully.

It fails as expected if there is a change to the function documentation:
https://github.com/ann0see/jamulus/actions/runs/3505130530

Other change doesn't make the check fail: https://github.com/ann0see/jamulus/actions/runs/3505127551

CHANGELOG: SKIP
Context: Fixes an issue?
No. But related to #1737

Does this change need documentation? What needs to be documented and how?

No

Status of this Pull Request
Review by @hoffie

What is missing until this pull request can be merged?
Theoretical review. I might not have thought about all possible cases where this check should be run.

Checklist

• I've verified that this Pull Request follows the general code principles
• I tested my code and it does what I want
• My code follows the style guide
• I waited some time after this Pull Request was opened and all GitHub checks completed without errors.
• I've filled all the content above

[hoffie]

Looks good to me.

We might even drop the secret in the env fully.

Worth a try. ;)

[ann0see]

Ok. Removing the token works:

Successful run without changes: https://github.com/ann0see/jamulus/actions/runs/3777431973/jobs/6421260779
Failed run with changes: https://github.com/ann0see/jamulus/actions/runs/3777433469

[ann0see]

I think after this is merged, we can remove even more permissions in GH settings.

[pljones]

Build is clean -> good.