Investigate schedule tasks to make sure execution completion return bool

[touhidurabir]

Describe the bug
Few of the schedule tasks have their executeActions method implemented in such way that it does not return any bool value but just void. But this cause error as it is expected to return a bool.

To Reproduce
Steps to reproduce the behavior(As pers @NateWr 's testing)

1. Do a clean installation of OJS main
2. See the mails related to automatically executed tasks .

Probably also possible to reproduce it via running the taks via cron or from command line via php tools/runScheduledTasks.php.
What application are you using?
OJS main .

Additional information
Email log details as per @NateWr 's testing

[26-Oct-2022 17:36:26 UTC] [2022-10-26 17:36:26] production.DEBUG: From: Open Journal Systems <admin@mailinator.com>
To: Open Journal Systems <admin@mailinator.com>
Subject: Deposit DOIs with configured registration agency - 6359701a90692 -
 Error
MIME-Version: 1.0
Date: Wed, 26 Oct 2022 17:36:26 +0000
Message-ID: <05e8547553df1d99f4f68b8f5a0e8711@mailinator.com>
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Your Open Journal Systems installation automatically executed and finished =
this task and you can download the log file here: http://localhost:8000/ind=
ex/admin/downloadScheduledTaskLogFile?file=3DDepositDOIswithconfiguredregis=
trationagency-6359701a90692-20221026.log  

[26-Oct-2022 17:36:26 UTC] [2022-10-26 17:36:26] production.DEBUG: From: Open Journal Systems <admin@mailinator.com>
To: Open Journal Systems <admin@mailinator.com>
Subject: Remove unvalidated expired users - 6359701a9991e - Error
MIME-Version: 1.0
Date: Wed, 26 Oct 2022 17:36:26 +0000
Message-ID: <fac23ff27cdb1fae2259c523bb3c38c8@mailinator.com>
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Your Open Journal Systems installation automatically executed and finished =
this task and you can download the log file here: http://localhost:8000/ind=
ex/admin/downloadScheduledTaskLogFile?file=3DRemoveunvalidatedexpiredusers-=
6359701a9991e-20221026.log  

[26-Oct-2022 17:36:26 UTC] [2022-10-26 17:36:26] production.DEBUG: From: Open Journal Systems <admin@mailinator.com>
To: Open Journal Systems <admin@mailinator.com>
Subject: An automated email sent to editors with outstanding tasks -
 6359701a9d6f3 - Error
MIME-Version: 1.0
Date: Wed, 26 Oct 2022 17:36:26 +0000
Message-ID: <7131f8dfe49aeae39b4d6b5dccada0cc@mailinator.com>
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Your Open Journal Systems installation automatically executed and finished =
this task and you can download the log file here: http://localhost:8000/ind=
ex/admin/downloadScheduledTaskLogFile?file=3DAnautomatedemailsenttoeditorsw=
ithoutstandingtasks-6359701a9d6f3-20221026.log  

[26-Oct-2022 17:36:35 UTC] [2022-10-26 17:36:35] production.DEBUG: From: Open Journal Systems <admin@mailinator.com>
To: Open Journal Systems <admin@mailinator.com>
Subject: Usage statistics file loader task - 63597023b9816 - Error
MIME-Version: 1.0
Date: Wed, 26 Oct 2022 17:36:35 +0000
Message-ID: <199b3e9a81ae8b509cb816b6b6a2f052@mailinator.com>
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Your Open Journal Systems installation automatically executed and finished =
this task and you can download the log file here: http://localhost:8000/ind=
ex/admin/downloadScheduledTaskLogFile?file=3DUsagestatisticsfileloadertask-=
63597023b9816-20221026.log  

[touhidurabir]

@asmecher PRs to review

pkp-lib --> #8401
ojs --> pkp/ojs#3603 [Test Only]

As I have checked, no need for any PR for the OMP and OPS either .

[asmecher]

Merged the pkp-lib PR, thanks! I'll leave the submodule updates for now, rather than causing merge conflicts for others on the team.