Prevent being able to depend on a library that's not declared in artifacts.bzl

[lolski]

Right now, it is possible for packages inside Grakn Core to depend on libraries declared in artifacts.bzl of other repositories.

For example, take the following example where Grakn Core also needs to load artifacts.bzl from Grabl Tracing:

load("//dependencies/maven:artifacts.bzl",
graknlabs_grakn_core_artifacts = "artifacts")
load("@graknlabs_grabl_tracing//dependencies/maven:artifacts.bzl",
graknlabs_grabl_tracing_artifacts = "artifacts")
load("@graknlabs_dependencies//library/maven:rules.bzl", "maven")

maven(
        graknlabs_grabl_tracing_artifacts +
        graknlabs_grakn_core_artifacts,
)

There's nothing that prevents Grakn Core to load Maven packages declared in the artifacts.bzl coming from Grabl Tracing. This is not ideal since Grakn Core should only be able to depend on Maven dependencies explicitly declared in artifacts.bzl.