Add regression test for https://github.com/sass/dart-sass/issues/2208… #1449

Job	Run time
Language \| Dart Sass \| Dart stable	57s
JS API \| Pure JS \| Node lts/* \| ubuntu-latest	1m 30s
Language \| Dart Sass \| Dart dev	59s
JS API \| Embedded \| Node lts/* \| ubuntu-latest	4m 48s
JS API \| Pure JS \| Node lts/* \| windows-latest	3m 49s
JS API \| Embedded \| Node lts/* \| windows-latest	6m 13s
JS API \| Pure JS \| Browser	1m 24s
JS API \| Pure JS \| Node lts/* \| macos-latest	2m 29s
JS API \| Embedded \| Node lts/* \| macos-latest	7m 46s
JS API \| Pure JS \| Node lts/-1 \| ubuntu-latest	1m 23s
Lint spec files	21s
JS API \| Embedded \| Node lts/-1 \| ubuntu-latest	4m 51s
JS API \| Pure JS \| Node lts/-2 \| ubuntu-latest	1m 20s
Static analysis	18s
JS API \| Embedded \| Node lts/-2 \| ubuntu-latest	4m 48s
JS API \| Pure JS \| Node lts/-3 \| ubuntu-latest	1m 25s
JS API \| Embedded \| Node lts/-3 \| ubuntu-latest	5m 0s
Unit tests	35s
	49m 56s

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