Previously, the `validate-commit-message` gulp task was using the
`git log ... ^r1 r2` syntax to list commits between the base branch and
the current head. This didn't work as expected on Windows, because `^`
is the escape character. As a result, the command was equivalent to
`git log ... r1 r2` on Windows, which essentially logs all commits
reachable from either `r1` or `r2`.
This commit fixes it by switching to git's
[double-dot range notation][1] (`r1..r2`), which is an alias for the
`^r1 r2` syntax and works correctly on all platforms.
[1]: https://git-scm.com/docs/gitrevisions#_dotted_range_notationsFixes#16830
PR Close#28780
Stop execution when an error happens in `validate-commit-message` gulp
task and ensure the error message is printed at the bottom.
Fixes#16829
PR Close#28780