submodule: update spawn submodule for any_io_executor

Signed-off-by: Casey Bodley <cbodley@redhat.com>

diff --git a/src/spawn b/src/spawn
index 9ee6d12f35ab2fa48b469f13b4830a5e5cfde45e..03d9e1b949b3f7f3c8036ba0e8b35a49c305a03e 160000 (submodule)
--- a/src/spawn
+++ b/src/spawn
@@ -1 +1 @@
-Subproject commit 9ee6d12f35ab2fa48b469f13b4830a5e5cfde45e
+Subproject commit 03d9e1b949b3f7f3c8036ba0e8b35a49c305a03e