fix: add -Encoding ASCII to Set-Content to prevent npm auth BOM issue

Jenkinsfile

@@ -68,7 +68,7 @@ pipeline {
             steps {
                 withCredentials([usernamePassword(credentialsId: 'NEXUS_CREDS', passwordVariable: 'NPM_PASS', usernameVariable: 'NPM_USER')]) {
                     bat """
-                        powershell -NonInteractive -Command "Set-Content .npmrc ('//nexus.xuqinmin.com/repository/npm-hosted/:_auth=' + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(\$env:NPM_USER + ':' + \$env:NPM_PASS)))"
+                        powershell -NonInteractive -Command "Set-Content .npmrc ('//nexus.xuqinmin.com/repository/npm-hosted/:_auth=' + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(\$env:NPM_USER + ':' + \$env:NPM_PASS))) -Encoding ASCII"
                         npm publish --registry %NEXUS_REGISTRY%
                     """
                 }