update install samtools

[lbergelson]

Description

Please explain the changes you made here.
Explain the motivation for making this change. What existing problem does the pull request solve?

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[lbergelson]

@cmnbroad I think this fixes it, provided tests pass. It adds a few minutes of mucking around with apt-get upgrade, so maybe I should remove that. We might also want to move to samtools 1.21.0 but I don't want to move it out from under you.

[cmnbroad]

Looks good to me, assuming tests pass. Thanks for fixing this @lbergelson.