lsp-roslyn: update to 4.12.0-3.24470.11 and fix stdpipe-path in Windows #5374

Job	Run time
test (ubuntu-latest, 27.2, false)	2m 12s
test (ubuntu-latest, 28.2, false)	2m 29s
test (ubuntu-latest, 29.4, false)	2m 43s
test (macos-latest, 28.2, false)	3m 40s
test (macos-latest, 29.4, false)	4m 13s
test (windows-latest, 27.2, false)	4m 2s
test (windows-latest, 28.2, false)	3m 7s
test (windows-latest, 29.4, false)	4m 13s
test (ubuntu-latest, snapshot, true)	1m 19s
test (macos-latest, snapshot, true)	2m 40s
test (windows-latest, snapshot, true)	5m 50s
	36m 28s

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