SPFarm: Suppress useless reboot triggered once a server joined the farm

[Yvand]

Pull Request (PR) description

I noticed this reboot and I don't see a good reason for it:

• SPS never requires the reboot of a server once it joined the farm using psconfigui.exe
• I took the time to test the suppression of the reboot with SharePoint Subscription / 2019 / 2016 / 2013: I could not notice any side effect, the server works normally as far as I could see

This Pull Request (PR) fixes the following issues

None

Task list

• [x] Added an entry to the change log under the Unreleased section of the file CHANGELOG.md. Entry should say what was changed and how that affects users (if applicable), and reference the issue being resolved (if applicable).
• [ ] Resource documentation added/updated in README.md.
• [ ] Resource parameter descriptions added/updated in README.md, schema.mof and comment-based help.
• [ ] Comment-based help added/updated.
• [ ] Localization strings added/updated in all localization files as appropriate.
• [ ] Examples appropriately added/updated.
• [ ] Unit tests added/updated. See DSC Community Testing Guidelines.
• [ ] Integration tests added/updated (where possible). See DSC Community Testing Guidelines.
• [ ] New/changed code adheres to DSC Community Style Guidelines.

---

This change is 

[codecov[bot]]

Codecov Report

Merging #1370 (007e666) into master (db53fd5) will decrease coverage by 0%. The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #1370   +/-   ##
======================================
- Coverage      84%     84%   -1%     
======================================
  Files         143     143           
  Lines       22204   22203    -1     
======================================
- Hits        18751   18750    -1     
  Misses       3453    3453           

Impacted Files	Coverage Δ
...PointDsc/DSCResources/MSFT_SPFarm/MSFT_SPFarm.psm1	89% <100%> (-1%)	:arrow_down: