Set default WSL version to 1 before install (#28)

In windows-2022 environment WSLv2 is now generally available and the default,
but it cannot work as GitHub actions are running on Azure cloud where nested
Hyper-V virtualization is not available.

GitHub will change the default WSL version back to WSLv1 in a future update
but to be future proof and not break again in case WSLv2 becomes properly
available in the future, we force it additionally in the action.

src/main/kotlin/net/kautler/github/action/setup_wsl/SetupWsl.kt

@@ -284,6 +284,16 @@ suspend fun verifyWindowsEnvironment() {
 }
 
 suspend fun installDistribution() {
+    exec(
+        commandLine = "wsl",
+        args = arrayOf("--set-default-version", "1"),
+        jsObject {
+            // ignore a failure in case WSLv2 is not available
+            // at all and thus `--set-default-version` is not
+            // a valid option for `wsl` at all
+            ignoreReturnCode = true
+        }
+    ).await()
     exec(
         commandLine = """"${path.join(distributionDirectory(), distribution.installerFile)}"""",
         args = arrayOf("install", "--root"),