CHIPIR: Remove Tektronix DMM4040/4050 LVDCOM IOCs

[rerpha]

As we have a streamdevice driver(#6211) for the tektronix dmm4040 and dmm4050 models, I would like to archive these two repos: https://github.com/ISISComputingGroup/EPICS-Tektronix_DMM_4050 https://github.com/ISISComputingGroup/EPICS-Tektronix_DMM_4040 and remove them from .gitmodules

acceptance criteria

• [x] Above repositories are archived
• [x] Above repositories are removed from .gitmodules

[rerpha]

https://github.com/ISISComputingGroup/EPICS/pull/351 https://github.com/ISISComputingGroup/IBEX/pull/8354