refactor: Move `ui.Theme.from_brand()` Sass code into an `.scss` file… #6076

Job	Run time
playwright-deploys-precheck (3.10)	1m 50s
check (3.12, ubuntu-latest)	2m 40s
check (3.12, windows-latest)	5m 43s
playwright-examples (3.12, chromium)	4m 9s
test-narwhals-integration	4m 1s
check (3.12, macOS-latest)	1m 46s
playwright-shiny (3.12, chromium)	4m 50s
playwright-examples (3.12, firefox)	4m 27s
check (3.11, ubuntu-latest)	2m 29s
playwright-shiny (3.12, firefox)	5m 55s
playwright-examples (3.12, webkit)	3m 56s
check (3.11, windows-latest)	6m 14s
playwright-shiny (3.12, webkit)	4m 34s
playwright-examples (3.11, chromium)	3m 32s
playwright-shiny (3.11, chromium)	4m 22s
check (3.11, macOS-latest)	1m 47s
playwright-shiny (3.11, firefox)	4m 49s
playwright-examples (3.11, firefox)	4m 9s
check (3.10, ubuntu-latest)	2m 31s
playwright-shiny (3.11, webkit)	5m 22s
playwright-examples (3.11, webkit)	3m 42s
check (3.10, windows-latest)	5m 29s
playwright-shiny (3.10, chromium)	4m 39s
check (3.10, macOS-latest)	2m 8s
playwright-examples (3.10, chromium)	4m 5s
playwright-shiny (3.10, firefox)	5m 5s
playwright-shiny (3.10, webkit)	4m 34s
check (3.9, ubuntu-latest)	2m 38s
playwright-examples (3.10, firefox)	4m 28s
check (3.9, windows-latest)	6m 35s
playwright-shiny (3.9, chromium)	4m 16s
playwright-examples (3.10, webkit)	4m 18s
playwright-shiny (3.9, firefox)	5m 21s
check (3.9, macOS-latest)	2m 47s
playwright-examples (3.9, chromium)	3m 40s
playwright-examples (3.9, firefox)	4m 30s
playwright-examples (3.9, webkit)	3m 57s
Deploy to PyPI	0s
	2h 31m 18s

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