Updated Dockerfile with new base, bcftools, plink, and picard.

[hylkedonker]

This pull request aims to address two points:

1. Running the workflow on UK biobank array data, the bcftools sort command in task picard_liftovervcf crashed with the error (from the stderr output):

Writing to /tmp/bcftools-sort.xYR9VD
[buf_flush] Error: cannot write to /tmp/bcftools-sort.xYR9VD/00001.bcf

On line:

bcftools sort -o "~{file_prefix}_~{reference}.vcf.gz" -O z \
        --max-mem "${memXmx_g}g" \
        "~{file_prefix}_~{reference}.vcf"

This problem appears to be specific to bcftools version 1.12. Upgrading to bcftools version 1.20 resolves the issue.

2. Support for ubuntu 20.04 ends in less than one year. Ubuntu 24.04 LTS is supported until April 2029.

Scope
This pull request only updates the Dockerfile, not the Docker image in liftover_plink_beds.wdl. I suggest that the maintainers (@yihchii ?) update the image accordingly (or, automatically with, e.g., github actions).