build(devcontainer): remove deprecated extension

[gmacario]

Fix #156

[gmacario]

NOTE: I am keeping this PR in draft since I realized there are three devcontainer.json in the repository and I haven't yet had the time to check whether bug #156 affects also the other files

[gmacario]

NOTE: I am keeping this PR in draft since I realized there are three devcontainer.json in the repository and I haven't yet had the time to check whether bug #156 affects also the other files

Done. @CuriousDolphin please verify

[gmacario]

I am scratching my head to understand why 9 tests out of 10 are failing, and also GitHub Copilot seems puzzled:

Anyone from the maintainers can give me a hint?

[CuriousDolphin]

I am scratching my head to understand why 9 tests out of 10 are failing, and also GitHub Copilot seems puzzled:

Anyone from the maintainers can give me a hint?

Don't worry, those logs in the tests are normal; they verify edge conditions. The tests fail due to a problem (probably with GitHub permissions) with the action that writes the summary comment on the tests, but the tests were performed correctly!
We are investigating to fix the action.