[build-presets] Enabled SourceKit-LSP tests on Linux
[build-presets] Enabled SourceKit-LSP tests on Linux

The SourceKit-LSP test failures seem to be caused by a bug of `swift test --parallel` on Linux. Since SourceKit-LSP now runs its test on Linux serially, we should be able to enable the tests again.

JGiola/swift,roambotics/swift,benlangmuir/swift,ahoppen/swift,roambotics/swift,benlangmuir/swift,roambotics/swift,apple/swift,JGiola/swift,apple/swift,benlangmuir/swift,ahoppen/swift,roambotics/swift,glessard/swift,atrick/swift,JGiola/swift,atrick/swift,benlangmuir/swift,roambotics/swift,glessard/swift,glessard/swift,JGiola/swift,ahoppen/swift,atrick/swift,apple/swift,benlangmuir/swift,roambotics/swift,atrick/swift,benlangmuir/swift,glessard/swift,ahoppen/swift,glessard/swift,apple/swift,apple/swift,JGiola/swift,JGiola/swift,apple/swift,glessard/swift,atrick/swift,atrick/swift,ahoppen/swift,ahoppen/swift