test: LinearProblem tests are no longer broken
#7350
| Job | Run time |
|---|---|
| 40m 44s | |
| 22m 37s | |
| 45m 3s | |
| 23m 58s | |
| 25m 54s | |
| 39s | |
| 40s | |
| 27m 20s | |
| 43m 39s | |
| 21m 8s | |
| 33s | |
| 17m 23s | |
| 34s | |
| 15m 56s | |
| 38m 23s | |
| 40s | |
| 5h 25m 11s |