Preserve ticks for displays across VMs

[dhalbert]

Fixes #6277.

SAMD21 ticks depend on the event system, which was getting reset between VM instantiations. But permanent displays depend on ticks being on to refresh. Fixed by not resetting the event system when ticks are in use.

@deshipu could you try this? Thanks.

[deshipu]

I just tried by flashing the adafruit-circuitpython-hallowing_m0_express-en_US-20220428-90b78fe.uf2 from S3 on my Hallowing M0 Express, but the screen remains dark.

[deshipu]

Checking out the branch and compiling it manually worked. The display now shows the REPL as it should.

[dhalbert]

@deshipu Thanks for testing!

I just tried by flashing the adafruit-circuitpython-hallowing_m0_express-en_US-20220428-90b78fe.uf2 from S3 on my Hallowing M0 Express, but the screen remains dark.

FYI, that is the last merge, not this PR. We don't push tentative PR builds to S3, but you can get the builds from the artifacts, e.g. https://github.com/adafruit/circuitpython/actions/runs/2236406159. If you click on a Details link above, and then choose Summary on that page, you'll get to a page with the artifacts. You can also find the appropriate build on the Actions link at the top of this page: https://github.com/adafruit/circuitpython/actions.

[gamblor21]

Code looks good to me. Relying on testing by @deshipu