ci: Add Borland 5.5 and 5.8 nightly CI jobs
These have long been running as standalone nightly builds. Add them to the nightly CI pipeline.
System updates will be applied on May 27th between 7am and 9am, EST (UTC-05:00). This site will have intermittent downtime during that time.
These have long been running as standalone nightly builds. Add them to the nightly CI pipeline.