Why doesn't CI work?

Question

Continuous Integration

Please help me understand why the simplest CI does not work after pushing.
There are two text files. Suppose the essence of CI is to output the contents of these files to the console after pushing to the gitlab master.
The problem is that after pushing to the master, I get this error message:

Here is the content of the config for CI:

test:
    cat 1.txt 2.txt | grep y123

Here is a link to the repository.
I understand that the config is incorrectly compiled, but I can’t figure out what exactly