fix: Set empty host for itms-services URL in SentryDistribution updater

[chenj-hub]

📜 Description

Explicitly set components.host = "" when constructing itms-services URLs. This ensures URLComponents generates the correct URL format with an empty host component.

💡 Motivation and Context

The buildUrlForInstall() method in SentryDistribution.Updater was generating malformed itms-services URLs. Without explicitly setting the host component, URLComponents produces URLs that don't work with iOS enterprise app distribution.

The itms-services scheme requires the format:

itms-services://?action=download-manifest&url=...

But without setting host = "", the generated URL was malformed.

💚 How did you test it?

Manual verification: itms-services URLs now generate in the correct format

$ swift -e '
  import Foundation

  let plistUrl = "https://example.com/manifest.plist"

  // WITHOUT the fix (buggy behavior)
  var componentsWithoutFix = URLComponents()
  componentsWithoutFix.scheme = "itms-services"
  // componentsWithoutFix.host = ""  // <- missing this line
  componentsWithoutFix.queryItems = [
    URLQueryItem(name: "action", value: "download-manifest"),
    URLQueryItem(name: "url", value: plistUrl)
  ]
  print("WITHOUT fix:")
  print(componentsWithoutFix.url?.absoluteString ?? "nil")
  print()

  // WITH the fix (correct behavior)
  var componentsWithFix = URLComponents()
  componentsWithFix.scheme = "itms-services"
  componentsWithFix.host = ""  // <- this is the fix
  componentsWithFix.queryItems = [
    URLQueryItem(name: "action", value: "download-manifest"),
    URLQueryItem(name: "url", value: plistUrl)
  ]
  print("WITH fix:")
  print(componentsWithFix.url?.absoluteString ?? "nil")
  '
WITHOUT fix:
itms-services:?action=download-manifest&url=https://example.com/manifest.plist

WITH fix:
itms-services://?action=download-manifest&url=https://example.com/manifest.plist