Removed Gills mutation from the list of available mutations for Lab Patient and Experiment scenarios

[Night-Pryanik]

Summary

Bugfixes "Removed Gills mutation from the list of available mutations for Lab Patient and Experiment scenarios"

Purpose of change

• Closes Gills trait unobtainable in character creation #57748.

Describe the solution

Removed Gills mutation from the list of available mutations for Lab Patient and Experiment scenarios as this mutation is the only one in that list that require crossing the threshold first.

Describe alternatives you've considered

None.

Testing

Started creating character, selected Experiment scenario, checked the list of available mutations.

Additional context

None.