Remove optimize-autoloader

[bencroker]

This PR removes the optimize-autoloader config option from the composer.json files, since according to the Composer docs:

By default, the Composer autoloader runs relatively fast. However, due to the way PSR-4 and PSR-0 autoloading rules are set up, it needs to check the filesystem before resolving a classname conclusively. This slows things down quite a bit, but it is convenient in development environments because when you add a new class it can immediately be discovered/used without having to rebuild the autoloader configuration.

And:

You should not enable any of these optimizations in development as they all will cause various problems when adding/removing classes. The performance gains are not worth the trouble in a development setting.

Source: https://getcomposer.org/doc/articles/autoloader-optimization.md#autoloader-optimization

Related discussion: craftcms/cms#12583

[khalwat]

Good call!