Avoid Thread.sleep during build

[hearnadam]

The comment in ScoverageSbtPlugin notes that this Thread.sleep(1000) was added to support Windows. Adding a 1s delay to otherwise performant builds is quite noticeable. The plugin could check the platform to avoid slowing down CI/CD, Linux, and Mac builds. Further, perhaps it's worth understanding why this issue is occurring in the first place.

sbt-scoverage/src/main/scala/scoverage/ScoverageSbtPlugin.scala

Lines 216 to 218 in eb406f5

	Thread.sleep(
	1000
	) // have noticed some delay in writing on windows, hacky but works

Happy to open a PR, but opened the issue to understand if there was a deeper problem here.

[ckipp01]

It was added before my time, so I'm really unsure what the back story was. Seeing the comment I'm open to adding a check here for the os and only doing this on windows.