0.14.0-m0

Set up Go 1.18 for the subctl consuming test

For tests relying on "local" builds, we need to set up Go explicitly
to match our requirements (1.18 or later now).

Since go mod download on its own doesn't deal with dependencies
through local replaces, we need to run go mod tidy to ensure all the
transitive dependencies are available.

Signed-off-by: Stephen Kitt <[email protected]>