Add an entry for FlyCI

[kgantchev]

FlyCI offers on average 2x faster and 2x cheaper MacOS runners for GitHub and it has exclusive access to M2 runners.

Here is the pricing breakdown:

Processor	vCPU	RAM (GB)	Label	Price on FlyCI	Price on GitHub
M1	4	7	flyci-macos-large-latest-m1	$0.06	N/A
M1	8	14	flyci-macos-xlarge-latest-m1	$0.12	$0.16
M2	4	7	flyci-macos-large-latest-m2	$0.08	N/A
M2	8	14	flyci-macos-xlarge-latest-m2	$0.16	N/A

[eggplants]

Discontinued: https://flyci.net/blog/flyci-discontinue-macos-runners