dillon1000/react

Track revs that intentionally fork the reconciler (#24671)

* Track revs that intentionaly fork the reconciler

When we fork the the "old" and "new" reconciler implementations, it can
be difficult to keep track of which commits introduced the delta
in behavior. This makes bisecting difficult if one of the changes
introduces a bug.

I've added a new file called `forked-revisions` that contains the list
of commits that intentionally forked the reconcilers.

In CI, we'll confirm that the reconcilers are identical except for the
changes in the listed revisions. This also ensures that the revisions
can be cleanly reverted.

* [TEST] Add trivial divergence between forks

This should fail CI. We'll see if the next commit fixes it.

* [TEST] Update list of forked revisions

This should fix CI

* Revert temporary fork

This reverts the temporary fork added in the previous commits that was
used to test CI.

* Update error message when CI fails