PM-1822 will change the interface between DSI and sys-perf evergreen yamls. To minimize the risk of breaking non-master branches and the overhead of multiple backports during PM-1822, we wish to "freeze" the version of DSI in use on the following projects:

1. sys-perf v4.4
2. perf v4.4
3. sys-perf v4.2
4. perf v4.2
5. sys-perf v4.0
6. perf v4.0
7. sys-perf v3.6
8. perf v3.6

To do this we will create a "legacy" branch of DSI and modify non-master evergreen yamls to use this. This means that any changes to DSI will not be usable by old perf projects unless those changes are backported.

At the end of PM-1822 we could selectively bring the required projects back up to DSI master or leave these projects "forever frozen".