[mono] Mark a test with changed behavior to WindowsOnly
[mono] Mark a test with changed behavior to WindowsOnly

`Microsoft.Build.UnitTests.Move_Tests.MoveLockedFile`
- this was marked as failing on netcore
- It expects to fail trying to move a "locked"(open for writing) file
- this test passed on mono <=5.18.1 but the behavior changed to match
dotnet after that.
- So, essentially, it is useful only on Windows/full framework now.

mono/msbuild,mono/msbuild,mono/msbuild,mono/msbuild