Truncating mypy_primer output per project #14059
Description
If there is a lot of mypy_primer output from a single project, the mypy primer is truncated so that output from some projects may not be visible at all. It could be better if we'd separately truncate the output of each project. We could still have a global output limit that is, for example, 3x the per-project output limit, to avoid huge output if a change breaks everything.