[move-examples] Actually fail tests when test fail
[move-examples] Actually fail tests when test fail

run_tests_for_pkg was running tests, however it was not correctly interpreting
the result of run_move_unit_tests, so it was not actually blocking diffs as
intended!

These should probably be consolidated with the way the framework tests are
being run but for now this is an ez win to stop these from breaking.

Test Plan:

Before I ran cargo nextest locally and it passed with breakages
After I ran cargo nextest locally and it failed as intended

cargo nextest run -p move-examples

aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core