Update build.yml

Bump the 5.8 train to 5.8.1

Author: compnerd

.github/workflows/build.yml

@@ -33,8 +33,8 @@ jobs:
             tag: 5.7.3-RELEASE
             options: ''
 
-          - branch: swift-5.8-release
-            tag: 5.8-RELEASE
+          - branch: swift-5.8.1-release
+            tag: 5.8.1-RELEASE
             options: ''
 
           - branch: development