[TASK] Clean up ext_emconf.php files

This removes the no longer evaluated option
`uploadfolder` from ext_emconf.php files.

Additionally, `clearCacheOnLoad => 0` is
removed, since this is the default.

Resolves: #96898
Releases: main, 11.5
Change-Id: I99379d6066e53abd67fd8e6a1f32638b597ea1c6
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/73520


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>