Bump pub to 048e3ad2b5e1b4ebe6883addbc95722be6904a7b

Changes:
```
> git log --format="%C(auto) %h %s" 0cbaf7a..048e3ad
 https://dart.googlesource.com/pub.git/+/048e3ad2 Add a spinner while validating before publishing (3776)
 https://dart.googlesource.com/pub.git/+/e5fdcf81 Fix terminal-detection logic for progress bar (3775)
 https://dart.googlesource.com/pub.git/+/16a79e2a Fix `global deactivate` on case-insensitive but case-preserving file systems (3774)
 https://dart.googlesource.com/pub.git/+/7493fad6 Updated documentation on entrypoint.acquireDependencies (3771)
 https://dart.googlesource.com/pub.git/+/faf9fa7e Info when publishing <3.0.0 constraint that is interpreted as <4.0.0 (3752)
 https://dart.googlesource.com/pub.git/+/bfaf3585 Validate package name in `pub global activate` (3735)
 https://dart.googlesource.com/pub.git/+/e84eefea Verify token characters when added and when used (3732)
 https://dart.googlesource.com/pub.git/+/60576f89 Correct spelling of 'publishing' (3767)
 https://dart.googlesource.com/pub.git/+/cb2f4b34 Bump actions/checkout from 3.2.0 to 3.3.0 (3763)
 https://dart.googlesource.com/pub.git/+/fc06561d Bump dart-lang/setup-dart from 1.3 to 1.4 (3764)
 https://dart.googlesource.com/pub.git/+/c6af8ff0 `dart pub remove`: Remove top-level key if empty after operation. (3758)
 https://dart.googlesource.com/pub.git/+/37692d8d Stop using always_throws (3765)
 https://dart.googlesource.com/pub.git/+/3ce46a32 Normalize pub.dartlang.org to pub.dev when reading lockfile (3754)
 https://dart.googlesource.com/pub.git/+/ab86f1e0 Add missing space in directory help text (3756)
 https://dart.googlesource.com/pub.git/+/14b13103 Fix `outdated`s handling of non-existent packages (3751)
 https://dart.googlesource.com/pub.git/+/56be1ca4 Fix typos in `dart pub add --help` (3750)
 https://dart.googlesource.com/pub.git/+/f698c43d Merge pull request 3746 from dart-lang/cherry_pick_conditional_sdk_rewrite
 https://dart.googlesource.com/pub.git/+/1bfb295d Merge branch 'master' into cherry_pick_conditional_sdk_rewrite
 https://dart.googlesource.com/pub.git/+/20f7daa9 Validate files don't differ in case only (3740)
 https://dart.googlesource.com/pub.git/+/9f41ae10 Only rewrite sdk constraints after dart 3
 https://dart.googlesource.com/pub.git/+/ea11b0d2 Only rewrite sdk constraints after dart 3 (3739)
 https://dart.googlesource.com/pub.git/+/12a2af4d Add and enforce require_trailing_commas (3728)
 https://dart.googlesource.com/pub.git/+/27c5cbd5 Only output errors during implicit resolution (3689)
 https://dart.googlesource.com/pub.git/+/e51b160b Remove features for migrating to null safety (3713)
 https://dart.googlesource.com/pub.git/+/f3cf3ac9 Add dependency kind information to `outdated --json` (3714)
 https://dart.googlesource.com/pub.git/+/0ee46ee0 Don't warn about overrides (3684)

```

Diff: https://dart.googlesource.com/pub.git/+/0cbaf7a2fb8c8ca543c6f222bf25d5f5c63abbf3..048e3ad2b5e1b4ebe6883addbc95722be6904a7b/
Change-Id: I9558072f3057c028f94c786f1dcdd8f48f42f39b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/281400
Reviewed-by: Sarah Zakarias <zarah@google.com>
Reviewed-by: Jonas Jensen <jonasfj@google.com>
Commit-Queue: Sigurd Meldgaard <sigurdm@google.com>

CHANGELOG.md

@@ -141,6 +141,20 @@ The null safety migration tool (`dart migrate`) has been removed.  If you still
 have code which needs to be migrated to null safety, please run `dart migrate`
 using Dart version 2.19, before upgrading to Dart version 3.0.
 
+#### Pub
+
+- To preserve compatibility with null-safe code pre Dart 3 Pub will interpret a
+  language constraint indicating a language version of `2.12` or higher and an
+  upper bound of `<3.0.0` as `<4.0.0`.
+
+  For example `>=2.19.2 <3.0.0` will be interpreted as `>=2.19.2 <4.0.0`.
+- `dart pub publish` will no longer warn about `dependency_overrides`. Dependency
+  overrides only take effect in the root package of a resolution.
+- `dart pub token add` now verifies that the given token is valid for including
+  in a header according to [RFC 6750 section
+  2.1](https://www.rfc-editor.org/rfc/rfc6750#section-2.1). This means they must
+  contain only the characters: `^[a-zA-Z0-9._~+/=-]+$`. Before a failure would
+  happen when attempting to send the authorization header.
 ## 2.19.0
 
 ### Language

DEPS

@@ -157,7 +157,7 @@ vars = {
   "path_rev": "a95f1e911dc9e2d407662c03edab0d550f2d1fa5",
   "pool_rev": "51f1131f707f81c5c9120bed5d290c8be83dc5d3",
   "protobuf_rev": "75bc380a6e9601565606a13dee16c5ab2bf5019c",
-  "pub_rev": "0cbaf7a2fb8c8ca543c6f222bf25d5f5c63abbf3", # manually rev'd
+  "pub_rev": "048e3ad2b5e1b4ebe6883addbc95722be6904a7b", # manually rev'd
   "pub_semver_rev": "e9c600c40986f6468b657a0ef967b32d668f4661",
   "shelf_rev": "9d1fb8ac5db71885bf8621e3a58cd5dd93ab6f02",
   "source_map_stack_trace_rev": "a60ef54b36147b103d8b7d0317d6b578ebf874cc",