Use Chromium mirror for archive dependency (#48509)

The archive dependency is currently being pulled directly from github which is not the desired workflow (see context in b/313920867)

This change migrates the source of the archive dependency to be the already exsiting auto-updated mirror.

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

DEPS

@@ -677,7 +677,7 @@ deps = {
 
    # Dart packages
   'src/flutter/third_party/pkg/archive':
-  Var('github_git') + '/brendan-duncan/archive.git' + '@' + '9de7a0544457c6aba755ccb65abb41b0dc1db70d', # 3.1.2
+  Var('chromium_git') + '/external/github.com/brendan-duncan/archive.git' + '@' + '9de7a0544457c6aba755ccb65abb41b0dc1db70d', # 3.1.2
 
   'src/flutter/third_party/pkg/equatable':
   Var('github_git') + '/felangel/equatable.git' + '@' + '2117551ff3054f8edb1a58f63ffe1832a8d25623', # 2.0.5