Increase path_selection coverage to > 10%

[gordon-klotho]

❯ go test -cover ./pkg/engine2/path_selection
ok      github.com/klothoplatform/klotho/pkg/engine2/path_selection     0.009s  coverage: 13.9% of statements

Standard checks

• Unit tests: ✅
• Docs: n/a
• Backwards compatibility: ✅

[jhsinger-klotho]

should also add cases for in graph, but unrelated to downstream/upstream (checking that it uses the undirected graph to determine weight)

[gordon-klotho]

👍 was planning on doing that (among other changes) for the +7% this week

[jhsinger-klotho]

not blocking, but i dont think the unit tests really cover that much of the functionality of those methods because they only have 2 simple cases, so we should add more to those. the 13% seems like it might be because a lot of the code path is touched although we need to add in tests for more variation of how we would expect it to behave given certain inputs