ext/mysqli: Skip test that needs superuser

[NattyNarwhal]

This test needs CREATE DATABASE and CREATE SERVER, and will fail in the cleanup step if it doesn't have it. If the test is running as a user that can't do these, then we should skip instead of borking.

Alternative to GH-17466.

[kamil-tekiela]

Can you explain why is useful to run the tests with a user who doesn't have the full permissions? What does it accomplish?

[NattyNarwhal]

Setting up a CI environment that isn't (yet) containerized; see GH-17258. Because of that, I'm a little hesitant to grant the CI DB user more than all privileges on a specific DB. That said, maybe GRANT CREATE, DROP ON *.* might not be too bad.

[kamil-tekiela]

Setting up a CI environment that isn't (yet) containerized; see GH-17258. Because of that, I'm a little hesitant to grant the CI DB user more than all privileges on a specific DB. That said, maybe GRANT CREATE, DROP ON *.* might not be too bad.

Even if it's not containerized, you'd want to be only ever running it on a test system. If for some reason, you still can't provide full permissions, then it is ok for some tests to fail as it points out flaws in the CI setup. We need full permissions in CI and if we don't have it then it means it's not set up correctly.

I'm still not convinced that we want to modify this test file.