Fix CI on Windows (#1861)

Fix bad assertion: `IoUtils.getSystemModuleCacheDir()` uses the actual
OS env, but the test hard-codes `isWindows` to false.

pkl-executor/src/test/kotlin/org/pkl/executor/ExecutorOptionsTest.kt

@@ -32,7 +32,7 @@ class ExecutorOptionsTest {
       System.setProperty("user.home", home.toString())
       assertThat(ExecutorOptions.defaultModuleCacheDir(home, false, mapOf()))
         .isEqualTo(home.resolve(".cache").resolve("pkl"))
-      assertThat(ExecutorOptions.defaultModuleCacheDir(home, false, mapOf()))
+      assertThat(ExecutorOptions.defaultModuleCacheDir())
         .isEqualTo(IoUtils.getSystemModuleCacheDir())
     } finally {
       System.setProperty("user.home", original)