updating htslib to 1.21

[erinyoung]

There's a new version of htslib!

I copied the files from 1.20.c and updated the software version ARG.

 diff htslib/1.20.c/Dockerfile htslib/1.21/Dockerfile 
2c2
< ARG HTSLIB_VER="1.20"
---
> ARG HTSLIB_VER="1.21"

Pull Request (PR) checklist:

• Include a description of what is in this pull request in this message.
• The dockerfile successfully builds to a test target for the user creating the PR. (i.e. docker build --tag samtools:1.15test --target test docker-builds/samtools/1.15 )
• Directory structure as name of the tool in lower case with special characters removed with a subdirectory of the version number (i.e. spades/3.12.0/Dockerfile)
  • (optional) All test files are located in same directory as the Dockerfile (i.e. shigatyper/2.0.1/test.sh)
• Create a simple container-specific README.md in the same directory as the Dockerfile (i.e. spades/3.12.0/README.md)
  • If this README is longer than 30 lines, there is an explanation as to why more detail was needed
• Dockerfile includes the recommended LABELS
• Main README.md has been updated to include the tool and/or version of the dockerfile(s) in this PR
• Program_Licenses.md contains the tool(s) used in this PR and has been updated for any missing

[Kincekara]

Thank you for the update! Looks good. I just changed the version in readme.
Deploy link: https://github.com/StaPH-B/docker-builds/actions/runs/11106589772

[erinyoung]

I'm so sorry about the README! Thank you for catching that!!!