remove doubled cache instruction

[shuryoka]

yaml file parsers are marking the cache instruction as doubled - this commit removes the second ocurrance as it is an exact copy of the first one

[ribalba]

@dan-mm could you please take a look. I think we needed the caching for venv?

[dan-mm]

@ribalba - the caching is still there, what was removed was an unnecessary duplicate

[ArneTR]

LGTM. Just talked to Didi, was just a visual oversight from him. Can be merged