Commit de7eaa9d erroneously added as a passing condition the new
job "unit_tests_gporca" to the compiled binary bin_gpdb_*. This led to a
pipeline validation failure because the orca unit test job does not
really do anything to the compiled binary. Commit 1bc0a548
attempted to fix that by doubling down on pretending the unit test job
*does* depend on the binary as an input. But it changed only the
generated pipeline YAML, not the template.

This patch fixes the pipeline validation with the right fix: we only
need the unit tests job as a passing condition for the GPDB source code
resource, not the binary.