**List of steps to reproduce**:
* Install MinervaNeue skin which has ResourceLoaderOOUIIconPackModule and defines its BundleSizeTest.php and bundlesize.config.json
* Install Femiwikia larger skin(https://www.mediawiki.org/wiki/Skin:Femiwiki) which sets SkinOOUIThemes than Minerva and set it to the default skin.
* Run PHPUnit.
**What happens?**:
There is 1 failureBundleSizeTest.php tests with `MediaWikiServices::getInstance()->getMainConfig()->get( 'DefaultSkin' )` skin,
so if the default skin is larger then the target of the test, there is failures: ([[ https://github.com/lens0021/FemiwikiSkin/runs/5953854294?check_suite_focus=true#step:15:1344 | full log ]])
```
1) MediaWiki\Skins\MinervaNeue\Tests\Structure\BundleSizeTest::testBundleSize
skins.minerva.mainMenu.icons is less than 409.6
Failed asserting that 410 is less than 409.60000000000002.
/workspace/src/tests/phpunit/structure/BundleSizeTest.php:59
/workspace/src/tests/phpunit/MediaWikiIntegrationTestCase.php:467
```
The theme that the Femiwiki skin uses is a custom OOUI theme, but changing it to Apex theme results in the same failure. ([[ https://github.com/lens0021/FemiwikiSkin/runs/5953976134#step:15:1345 | log ]])
The failure disappears when removing `SkinOOUIThemes`. ([[ https://github.com/lens0021/FemiwikiSkin/compare/66cbc7d88e4165121538db693231f77bf56a8844..25d0efa4310c00c709186ac31f386755e2929b0a | The comparison between two commits ]] / [[ https://github.com/lens0021/FemiwikiSkin/runs/5953851927 | log ]])
```lang=diff, name=skins/Femiwiki/skin.json
- "SkinOOUIThemes": {
- "femiwiki": "Femiwiki"
- },
```
**What should have happened instead?**:
There should be no failuare.
**Software version**:
MediaWiki: 1.39 a01dbf1e075f10594729b4ffe927293915344cd6
MinervaNeue: 916e8bc9c1b47eb09f8d032dd5a2e18e3b0ddec2