Fetch read length info for run instead of just lane 1

[kjellinjonas]

Description:

Previously, get_metadata.py reported the read and index length based on the information from lane 1 which could be misleading in some cases. Therefore, it was decided that the script should be updated so that it shows the read length setting for the run instead.
In this update, this is achieved by fetching length information from RunInfo.xml

Also updated actions/cache from v2 --> v4.2.2 to enable automatic testing

Risk analysis:

The scripts will most likely fail if there are updates to the structure of the RunInfo.xml file. However, the damage from this would be minimal and should be noticed immediately.

Validation procedure:

Run ngi work flow, generate reports and makes sure that the expected read and index lengths are printed in the report.