/release: do not require a "Rebase to <version>" title

Today, I want to release Git for Windows v2.39.0(2), a version for which
no upstream Git version was released (v2.39.1 is still a few weeks out:
https://lore.kernel.org/git/xmqqcz8csz5k.fsf@gitster.g/).

So I created a Pull Request with a minor change that I wanted to do
anyway, as an excuse for the Git artifacts build to run.

We already allow this with `/git-artifacts`. Let's allow that also with
the `/release` command.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

GitForWindowsHelper/slash-commands.js

@@ -203,7 +203,6 @@ module.exports = async (context, req) => {
             if (owner !== 'git-for-windows'
              || repo !== 'git'
              || !req.body.issue.pull_request
-             || !req.body.issue.title.match(/^Rebase to v?[1-9]\S*$/)
              ) {
                 return `Ignoring ${command} in unexpected repo: ${commentURL}`
              }