ci: avoid depending on stack job for test-bootstrap jobs

This patch makes test-bootstrap related ci jobs only depend on
hadrian-ghc-in-ghci job to finish, consistent with other jobs in the
full-build stage generated by gen_ci.hs. This allows the jobs to be
spawned earlier and improve overall pipeline parallelism.

(cherry picked from commit e684c406)
(cherry picked from commit 4884eb08)
(cherry picked from commit f3a9d4ec)