build: add Windows release artifacts (#140)

Author: zetaloop

.github/workflows/build.yaml

@@ -33,6 +33,12 @@ jobs:
           - name: mcp-auth-proxy-darwin-arm64
             os: darwin
             arch: arm64
+          - name: mcp-auth-proxy-windows-amd64.exe
+            os: windows
+            arch: amd64
+          - name: mcp-auth-proxy-windows-arm64.exe
+            os: windows
+            arch: arm64
 
     steps:
       - name: Checkout repository