Perviously, it was not immediately clear what branches a PR would merge
into during the merge process. This prompt allows for caretakers to
understand and acknowledge where the PR will merge to.
PR Close#39333
Adds support for a caretaker note label to the merge script.
Whenever a configured label is applied, the merge script will
not merge automatically, but instead prompt first in order
to ensure that the caretaker paid attention to the manual
caretaker note on the PR. This helps if a PR needs special
attention.
PR Close#37595