Make ZipperBams hanlde program name collisions

[bwlang]

I had to add --no-PG to my ubam generation code to avoid name collisions.
to reproduce create a ubam with samtools cat and samtool collate.
then use samtools collate to product the aligned bam.

[bwlang]

here is the specific error:
java.lang.IllegalArgumentException: Program record with group id samtools already exists in SAMFileHeader!

[nh13]

@bwlang thanks for reporting this and good to hear from you!

I think this was fixed in #963, which went out in 2.3.0

I ran

samtools cat test.bam | samtools collate -O /dev/stdin> unmapped.bam
samtools collate test.bam > mapped.bam
cat mapped.bam | java -Xmx8G -jar target/scala-2.13/fgbio-2.5.0-f93fdfbb-SNAPSHOT.jar ZipperBams -u unmapped.bam -r ref.fa > test.sam

and got no exception.

Feel free to reopen if there's still an issue!