[deps] remove references to archived repos (#161248)

- remove references to archived repos; test_reflective_loader, sse,
source_span, source_maps, pub_semver, pool and package_config

These have moved into the dart-lang/tools monorepo.

*List which issues are fixed by this PR. You must list at least one
issue. An issue is not required if the PR fixes something trivial like a
typo.*

- done as part of https://github.com/dart-lang/sdk/issues/56591

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [ ] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
https://dart.googlesource.com/external/github.com/flutter/flutter/+/ad5e1fe300b7bfe618f9c2f4a394f499eac6859c
diff --git a/DEPS b/DEPS
index 5ad9f2c..b29d12a 100644
--- a/DEPS
+++ b/DEPS
@@ -254,7 +254,7 @@
 deps = {
   'flutter/engine/src/flutter/third_party/dart': Var('dart_git') + '/sdk' + '@' + 'a1f5ee9861c73486ab3f9bdc8090c0d0342d5397',
 
-  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + '94c4d0568e147c1ee8b807447480b92756d7327a',
+  'flutter': Var('flutter_git') + '/mirrors/flutter' + '@' + 'ad5e1fe300b7bfe618f9c2f4a394f499eac6859c',
 
   'flutter/engine/src/flutter/third_party/depot_tools':
   Var('chromium_git') + '/chromium/tools/depot_tools.git' + '@' + '580b4ff3f5cd0dcaa2eacda28cefe0f45320e8f7',
diff --git a/commits.json b/commits.json
index 95242fc..f09a955 100644
--- a/commits.json
+++ b/commits.json
@@ -1,4 +1,4 @@
 {
-  "flutter":"94c4d0568e147c1ee8b807447480b92756d7327a",
+  "flutter":"ad5e1fe300b7bfe618f9c2f4a394f499eac6859c",
   "flutter/engine/src/flutter/third_party/dart":"a1f5ee9861c73486ab3f9bdc8090c0d0342d5397"
 }
\ No newline at end of file