Include PHP 8.3 in tested versions for PHPunit

[mikkamp]

Changes proposed in this Pull Request:

This PR changes the tested versions for PHPunit.

I switched it to running the default unit tests on PHP 8.2 and then included an additional test for the lowest (7.4) supported and highest (8.3) supported versions.

Note

Although the unit tests run successfully with PHP 8.3 we are still waiting on #2182 to be resolved before we can mark the extension as fully compatible.

Detailed test instructions:

1. Check the workflow runs in this PR and confirm it has a successful unit test for PHP versions 7.4, 8.2, 8.3

Changelog entry

• Dev - Include PHP 8.3 in tested versions for PHPunit.

[codecov]

Codecov Report

Merging #2183 (4acff4a) into develop (2b9b5ae) will increase coverage by 1.2%.
Report is 51 commits behind head on develop.
The diff coverage is 71.4%.

Additional details and impacted files

@@             Coverage Diff             @@
##             develop   #2183     +/-   ##
===========================================
+ Coverage       58.2%   59.4%   +1.2%     
  Complexity      4127    4127             
===========================================
  Files            453     453             
  Lines          17691   16478   -1213     
===========================================
- Hits           10300    9788    -512     
+ Misses          7391    6690    -701     

Flag	Coverage Δ
php-unit-tests	59.4% <71.4%> (+1.2%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/DB/Table.php	9.1% <ø> (ø)
src/DB/TableInterface.php	0.0% <ø> (ø)
src/Infrastructure/GoogleListingsAndAdsPlugin.php	0.0% <ø> (ø)
src/Shipping/ZoneMethodsParser.php	98.4% <100.0%> (-0.1%)	⬇️
google-listings-and-ads.php	7.7% <0.0%> (+1.4%)	⬆️
src/DB/Migration/Migration20231109T1653383133.php	0.0% <0.0%> (ø)

... and 99 files with indirect coverage changes

[puntope]

✅ LGTM