Stop patching the private ops.testing._TestingModelBackend class #187
Description
Context
As _TestingModelBackend is a private class, no guarantees are made about compatibility, and the tests relying on patching this class will break in an upcoming ops release.
The patching is actually no longer required with recent versions of ops, so mostly the patching can just be removed, with the occasional add_network call potentially required.
What needs to get done
Remove the patching of _TestingModelBackend.
You can use these PRs as examples if needed:
If any assistance is required, please reach out to @canonical/charm-tech and we'll be happy to help!
Definition of Done
No private ops classes are patched.