Add positivity data along W^2=10 GeV^2 line

[kamillaurent]

This PR is to update positivity dataset for gluon, I added new datapoints along the W^2=10 GeV^2 line in kinematic_XGL.yaml and updated metadata.yaml. The baseline fit runcard does not need to be changed, since the dataset name is the same. @scarlehoff let me know if you have any question

[scarlehoff]

Please rebase this on top of master.

Also, remove the runcards you are adding, this PR should only update the example-nnpdf41.yml if any (and that one is in a different folder!)

[kamillaurent]

Ok, I rebased on master and removed the extra runcard, let me know if any other action is required

[scarlehoff]

hi @kamillaurent , you are still adding a lot of runcards. Look at "files changed"
The only runcard that needs to be modified is the one in n3fit/runcards/example-nnpdf41.yml which is the one only source of truth for the 4.1 runcard.

[kamillaurent]

@scarlehoff oh I see, should be fixed now

[scarlehoff]

Thanks. Let's me squash the commits then I'll merge.