End to end tests should work with toolchain-less SDKs

[euanh]

See #175

We should still have at least one test using SDKs which include toolchains, but since the default is now not to include them the tests need to exercise this option.

Ideally the toolchain will not need to be installed on the test system. This is not so much of a problem in CI, but we are trying to reduce the footprint left by running tests locally for development.