Allowing our pipeline to function with a sample size of one

[koncheto-broad]

Small bug discovered while experimenting with deletion. Required adding a new parameter to a numpy function call

Successful run with one sample: https://app.terra.bio/#workspaces/gvs-dev/GVS%20Tiny%20Quickstart%20hatcher/job_history/46db87ed-2060-4841-b8a3-8bf073d9a476

Successful run with two samples (verifying that the changes didn't mess anything up): https://app.terra.bio/#workspaces/gvs-dev/GVS%20Tiny%20Quickstart%20hatcher/job_history/108364b0-c220-45ba-aea9-884e925e65fa

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (ah_var_store@b338cc9). Click here to learn what that means.
The diff coverage is n/a.

❗ Current head 04f2d5a differs from pull request most recent head 6b737da. Consider uploading reports for the commit 6b737da to get more accurate results

Additional details and impacted files

@@               Coverage Diff                @@
##             ah_var_store     #8055   +/-   ##
================================================
  Coverage                ?   86.233%           
  Complexity              ?     35201           
================================================
  Files                   ?      2173           
  Lines                   ?    165012           
  Branches                ?     17791           
================================================
  Hits                    ?    142294           
  Misses                  ?     16388           
  Partials                ?      6330