Bump third-party/libswiftnav from 5c18c08 to c580b9d (#66)

dependabot[bot] · web-flow · commit f588e20bc7c7 · 2021-08-09T20:56:19.000Z
diff --git a/third-party/libswiftnav b/third-party/libswiftnav
@@ -1 +1 @@
-Subproject commit 5c18c08b3115bc5f6e2b5d3b0793033300aa6604
+Subproject commit c580b9d041a7b6727ea7efdfa3fc9e6443e902f0
