minor: simplify scripts and ensure we are able to rerun

[rnveach]

identified from https://github.com/sevntu-checkstyle/sevntu.checkstyle/blob/master/.ci/validation.sh#L20 when trying to run locally and running into issues,

sevntu.checkstyle/ $ ./.ci/validation.sh eclipse-cs

.....
fatal: destination path 'eclipse-cs' already exists and is not an empty directory.


sevntu.checkstyle/.ci-temp/eclipse-cs/ $ git status

HEAD detached at 10.0.0
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

    modified:  docs/partials/releases/5.0.0final/release_notes.html
    modified:  docs/sitemap.xml

no changes added to commit (use "git add" and/or "git commit -a")

[rnveach]

Looks like this may have been forgotten to undo.
See #828 (comment)

[rnveach]

Confirmed working on my local.

sevntu.checkstyle/ $ ./.ci/validation.sh eclipse-cs

....
[INFO] ------------------------------------------------------------------------
Target project eclipse-cs is already cloned, latest changes will be fetched and reset
HEAD is now at 6ab343b9 config: release 10.0.0
Eclipse-cs tag: 10.0.0
HEAD is now at 6ab343b9 config: release 10.0.0
[INFO] Error stacktraces are turned on.
....
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  17.543 s
[INFO] Finished at: 2022-10-29T13:00:55-04:00
[INFO] ------------------------------------------------------------------------

[rnveach]

For travis, s390x is having issues starting. That is why I was trying to run this job locally.