Update build.yml

Adopt the new automation of the Swift installer.  Adopt the extracted composite action.

Author: compnerd

.github/workflows/build.yml

@@ -24,15 +24,14 @@ jobs:
           - branch: development
             tag: DEVELOPMENT-SNAPSHOT-2021-06-12-a
 
-    steps:
-    - uses: actions/checkout@v2
-    - uses: seanmiddleditch/gha-setup-vsdevenv@master
-    - name: Install Swift
-      uses: ./.github/actions/install-swift
+    steps:    
+    - uses: compnerd/gha-setup-swift@main
       with:
         tag: ${{ matrix.tag }}
         branch: ${{ matrix.branch }}
 
+    - uses: actions/checkout@v2
+
     - name: Build
       run: swift build -v