Fix UnhandledFutureError if reading exit code fails

Relates to #69.

src/Internal/Windows/SocketConnector.php

@@ -102,7 +102,7 @@ public function connectPipes(WindowsHandle $handle, Cancellation $cancellation):
  $exitCode = $this->readExitCode($handle->exitCodeStream);
 
  $handle->joinDeferred->complete($exitCode);
- } catch (HandshakeException) {
+ } catch (\Throwable) {
  $handle->joinDeferred->error(new ProcessException("Failed to read exit code from process wrapper"));
  } finally {
  $handle->status = ProcessStatus::Ended;