Create a new base job: legacy-ipa-dsvm-base
Define 'irrelevant-files' in legacy-ipa-dsvm-base and remove them from
project.yaml. This means we only define 'irrelevant-files' once. Also
makes project.yaml much easier to read.
Fix the 'irrelevant-files' section to make sure we do test
when changes to 'requirements.txt'.
Remove the 'branches:' section from the experimental job
'ipa-tempest-dsvm-partition-pxe_ipmitool-tinyipa-python3'
Sort the jobs lists in project.yaml.
Change-Id: Idbace38e0558e8a80e2d405ea0f6a0698989e140
8ba851bf27