Ignore dashcircle pixel mismatches for mtltestprecompile

Change-Id: I2ac8052f3fb0a972746a5866898a6e455971889d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/458957
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
2 files changed