CI tests should not test installation or examples

[ufechner7]

Regular tests should only test code in the src folder.

The

• examples
• install script

etc should only be tested:

• manually, before a release
• every night via https://github.com/OpenSourceAWE/AWEMeta.jl/tree/main

Rational:
The installation tests and the example tests take too long and slow down progress on pull requests too much. Therefore, they should be executed less often.

[1-Bart-1]

You can also run the installation tests and example tests on merge to main.