Fix `test_window_state_assignment` testbed on macOS-arm64 #7348

Job	Run time
Pre-commit checks / Pre-commit Checks	37s
Check towncrier / Towncrier Checks	39s
Package Toga (cocoa) / Create Python Package	18s
Package Toga (android) / Create Python Package	24s
Package Toga (core) / Create Python Package	24s
Package Toga (demo) / Create Python Package	25s
Package Toga (dummy) / Create Python Package	32s
Package Toga (gtk) / Create Python Package	19s
Package Toga (iOS) / Create Python Package	17s
Package Toga (textual) / Create Python Package	17s
Package Toga (toga) / Create Python Package	26s
Package Toga (web) / Create Python Package	20s
Package Toga (winforms) / Create Python Package	25s
Test core (macos-latest, 3.9)	1m 13s
Test core (macos-latest, 3.10)	1m 3s
Test core (macos-latest, 3.11)	1m 0s
Test core (macos-latest, 3.12)	48s
Test core (macos-latest, 3.13)	54s
Test core (ubuntu-latest, 3.9)	58s
Test core (ubuntu-latest, 3.10)	54s
Test core (ubuntu-latest, 3.11)	56s
Test core (ubuntu-latest, 3.12)	1m 0s
Test core (ubuntu-latest, 3.13)	1m 10s
Test core (windows-latest, 3.9)	1m 58s
Test core (windows-latest, 3.10)	1m 44s
Test core (windows-latest, 3.11)	1m 33s
Test core (windows-latest, 3.12)	1m 51s
Test core (windows-latest, 3.13)	2m 38s
Coverage	31s
Testbed (macOS-x86_64)	8m 35s
Testbed (macOS-arm64)	6m 48s
Testbed (windows)	8m 36s
Testbed (linux-x11)	5m 16s
Testbed (linux-wayland)	5m 13s
Testbed (android)	10m 41s
Testbed (iOS)	8m 45s
Testbed (textual-linux)	1m 2s
Testbed (textual-macOS)	1m 10s
Testbed (textual-windows)	2m 17s
	1h 23m 57s

Provide feedback