Change CI branch's name in the PR template

Since we did another reset, we can go back to using the original name
which is more straightforward. While at it, I also removed the
extraneous space in "- branch" and shortened the line length to be less
than 72 characters.

.github/pull_request_template.md

@@ -5,6 +5,7 @@ Fixes # .
 - [ ] the `CHANGELOG.rst` was updated.
 - [ ] new and adjusted code is formated using `black` and `isort`.
 - [ ] the `Dataset`-version is updated when existing datasets are adjusted.
-- [ ] the branch was merged into the `continuous-integration/run-everything-over-the-weekend-v2`- branch.
+- [ ] the branch was merged into the
+      `continuous-integration/run-everything-over-the-weekend`-branch.
 - [ ] the workflow is running successful in `test mode`.
 - [ ] the workflow is running successful in `Everything` mode.