Bisect fail due to forwarded cherry pick

More context here https://bazelbuild.slack.com/archives/CGA9QFQ8H/p1743519038565329?thread_ts=1743476057.039839&cid=CGA9QFQ8H

User tried to bisect between 7.6.1..8.0.0. Since 7.6.1 was a cherry-picked release, bisect started at the merge base commit, which effectively changed the range to 7.0.0..8.0.0.

```
The good Bazel commit is not an ancestor of the bad Bazel commit, overriding the good Bazel commit to the merge base commit 0a2aac4e3c6f5ef98fc233e2ce83e44930edb188
```

However, because MODULE.bazel `include()` syntax was only included in 8.0.0 and cherry-picked to 7.2.0, the user's workspace is incompatible with 7.0.0 and thus, unable to start the bisect on 7.0.0.

Reproduce the bisect from 7.6.1 to 8.0.0 using a workspace that requires MODULE.bazel include() syntax, then inspect the bisect entry point and merge-base handling. Done means bisect can begin from a compatible revision or reports a clear actionable failure instead of selecting 7.0.0.

Written by the indexing model from the issue text.