tests/sys/psa_crypto*: remove test symlinks

[Einhornhool]

The PSA configuration tests used symlinks of the files from examples/psa_crypto. This lead to the issue that CI did not rebuild them for each of the tests and missed some boards with insufficient memories.

This PR removes the symlinks from the tests and cleans up some of the code.

Testing procedure

Run the tests successfully for all boards.

[MrKevinWeiss]

There is also a label to disable the test cache if we need it.

[riot-ci]

Murdock results

:heavy_check_mark: PASSED

545a4dd5e40b5eb48ace9d8df5719353946f1a98 tests/sys/psa_crypto_ecdsa: Make stacksize backend dependent

Success	Failures	Total	Runtime
153	0	153	03m:13s

Artifacts

• Documentation preview

[Einhornhool]

Thanks for cleaning this up!

For some reason, Github doesn't let me comment on the lines directly, but in several main.c files, you still have

    /* Needed in case only hashes are tested */
    (void)status;
    (void)start;

which is now superfluous, right?

Maybe it would also be a good idea to add a comment to the example_*.c files mentioning that they are copied from examples/psa_crypto.

Apart from that, LGTM :)

You're right. I updated the files :)

[mguetschow]

You may then squash everything together :+1: