internal/processtest: fail on WSL

[hajimehoshi]

os/exec doesn't work well?

[hajimehoshi]

~/ebiten$ GOOS=windows go test ./internal/processtest/
--- FAIL: TestPrograms (1.54s)
    --- FAIL: TestPrograms/issue1753.go (0.17s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2079.go (0.16s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2089.go (0.14s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2129.go (0.16s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2138.go (0.17s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2154_1.go (0.18s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2154_2.go (0.16s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2162.go (0.22s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
    --- FAIL: TestPrograms/issue2182.go (0.17s)
        processtest_test.go:50: exit status 1
            go: RLock \\wsl$\Ubuntu\home\hajimehoshi\ebiten\go.mod: Incorrect function.
FAIL
FAIL    github.com/hajimehoshi/ebiten/v2/internal/processtest   1.943s
FAIL

[hajimehoshi]

WSLENV=GOOS/w GOOS=windows go test ./internal/processtest/ also didn't work.

[hajimehoshi]

https://github.com/microsoft/WSL/issues/5762

[hajimehoshi]

#1864