Hi oOLukasOo ,
Unfortunately, there is no way to disable the Trial apps, rather you can disable the apps tab completely.
In that case end users will not be able to install any new application unless IT team does not jump in and deploy the applications for them.
To disable Apps tab please you can either do it manually by navigating to
Navigate to the following location(Windows): C:/Program Files(x86)/Common Files/Adobe/OOBE/Configs/(macOS): /Library/Application Support/Adobe/OOBE/Configs/ Locate and open the serviceconfig.xml file in Notepad (Windows) or TextEdit (macOS).
In the serviceeconfig.xml file, change the value of AppsPanel from true to False.
Else,
Create a new package with no apps included and while creating the package uncheck the option Show apps tab.

Note - You don't need to include any application apart from Creative cloud desktop application which will be included by default.
~Rohit