Remove custom userAgent

This is already provided by HTTPClient

Author: mattt

Sources/PackageRegistry/RegistryManager.swift

@@ -28,8 +28,6 @@ public enum RegistryError: Error {
     case invalidChecksum(expected: String, actual: String)
 }
 
-fileprivate let userAgent = "SwiftPackageManager/\(ToolsVersion.currentToolsVersion)"
-
 public final class RegistryManager {
     internal static var clientFactory: () -> HTTPClientProtocol = {
         var configuration = HTTPClientConfiguration()
@@ -62,8 +60,7 @@ public final class RegistryManager {
                     method: .head,
                     url: url,
                     headers: [
-                        "Accept": "application/vnd.swift.registry.v1",
-                        "User-Agent": userAgent
+                        "Accept": "application/vnd.swift.registry.v1"
                     ]
                 )
 
@@ -92,8 +89,7 @@ public final class RegistryManager {
             method: .get,
             url: registryBaseURL,
             headers: [
-                "Accept": "application/vnd.swift.registry.v1+json",
-                "User-Agent": userAgent
+                "Accept": "application/vnd.swift.registry.v1+json"
             ]
         )
 
@@ -141,8 +137,7 @@ public final class RegistryManager {
             method: .get,
             url: url,
             headers: [
-                "Accept": "application/vnd.swift.registry.v1+swift",
-                "User-Agent": userAgent
+                "Accept": "application/vnd.swift.registry.v1+swift"
             ]
         )
 
@@ -189,8 +184,7 @@ public final class RegistryManager {
             method: .get,
             url: url,
             headers: [
-                "Accept": "application/vnd.swift.registry.v1+zip",
-                "User-Agent": userAgent
+                "Accept": "application/vnd.swift.registry.v1+zip"
             ]
         )