Update build.yml

Bump the toolchain to 5/20 snapshot.  This includes a change to the Foundation Process RunLoop monitoring which should help improve stability.

Author: compnerd

.github/workflows/build.yml

@@ -38,7 +38,7 @@ jobs:
             options: ''
 
           - branch: development
-            tag: DEVELOPMENT-SNAPSHOT-2023-04-01-a
+            tag: DEVELOPMENT-SNAPSHOT-2023-05-20-a
             options: ''
 
     name: Swift ${{ matrix.tag }}