Add E2E test for upgrade case, cert rotation

[viccuad]

Acceptance criteria

• Remove cert-manager from usual install tests: this is done to done once 1.17 is released, otherwise the 1.16 -> 1.17 upgrade test won't work, since 1.16 requires cert-manager to be installed
• Add new test for upgrading from 1.16 (previous cert-manager) to 1.17 (self-rotation).: Update the current e2e upgrade test already cover this scenario. There's no additional work to be done

[flavio]

assigned to 1.18, see the explanation of the only action to implement

[kravciak]

Cert-manager is now installed only if kubewarden <= 1.16 and removed after upgrade to 1.17.