Bump pub

New commits include:
```
$ git log --format="%C(auto) %h %s" 0e657414a472e74ca5dd76ae0db50cc060251dec..00c00e8adf9706bebe8f94483b7663c5f36f59d2
 00c00e8a Vendor tar (#2987)
 291705ca Being gradual migration to null-safety (#2988)
 c5f52a37 Fix CI (#2989)
 74040a45 Update to analyzer 1.5.0, migrate from deprecated AnalysisSession.getParsedUnit() (#2975)
 ce951d70 Fix dry-run tests for publishing  by ensuring there is a server to reject requests (#2978)
 018c9650 Update LICENSE (#2944)
 2614f15c Revert "Vendor package:tar and package:chunked_stream (#2932)" (#2940)
 12d9f457 Handle package:tar cancellations
 255a3091 Vendor package:tar and package:chunked_stream (#2932)
 86bf8b20 Handle relative git-url-paths correctly when --directory (#2919)
 3716a681 Let `pub add` fail if extra arguments are passed (#2927)
 a03ac729 Minor cleanup to reduce risk of using path.current (#2924)
 e87b7b66 Added null check for name in UserInfo class (#2918)
 056a8c9a pub deps --json (#2896)
 53a69e27 Fix .packages entries of relative path deps when using --directory (#2916)
 d6308efc pub upgrade command shows count of discontinued packages (#2908)
 51744805 Upgrade to the null safe versions of all dependencies (#2913)
 e0d538c7 Introduce .pubignore (#2787)
 79f3a8b9 pub outdated: added clear message when no outdated packages. (#2898)
 22463872 `cache clean` (#2904)
 11e7b2ce `publish --dry-run` informs that the server might do more checks (#2883)
 b6977d50 Remove untrue assert (#2884)
 35841f8d Merge branch 'cherry_picks_for_2_12'
 0db3255b Don't fail on failed status listing (#2877)
 53e8ecca Don't allow outdated taking arguments (#2872)
 e83a1dc1 Enable asserts when testing pub (#2754)
 178f2edb Add --directory option (#2876)
 5aadb70e Don't fail on failed status listing (#2877)
 4bf8a927 Remove unused field (#2878)
 73ad5426 Don't allow outdated taking arguments (#2872)
 9a70949e Use Dart library to read and write tar files (#2817)
 2f74230c Do not recommend decativating packages (#2871)
 b1697a27 Use full error message string in CommandResolutionFailedException (#2870)
 16a6210d Upgrade `downgrade --help`: `downgrade` actually updates `pubspec.lock` (#2859)
 6e240ea9 Use cached version listings as heuristic when prefetching (#2851)
 58152f7c Allow trailing slash in PUB_HOSTED_URL (#2856)
 b1bf9a33 Handle poor package-listing responses robustly. (#2847)
 d941bd24 Fix request metadata when overriding dependencyType (#2848)
```

Change-Id: Id7cc4c09e74c02a92bcafe1a9d9bab9431900540
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/199040
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Jonas Jensen <jonasfj@google.com>

.dart_tool/package_config.json

@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2021-05-05T10:52:59.908934",
+  "generated": "2021-05-10T19:21:13.245788",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -533,7 +533,7 @@
       "name": "pub",
       "rootUri": "../third_party/pkg/pub",
       "packageUri": "lib/",
-      "languageVersion": "2.11"
+      "languageVersion": "2.12"
     },
     {
       "name": "pub_semver",

CHANGELOG.md

@@ -59,6 +59,34 @@ Updated the Linter to `1.4.0`, which includes:
 - `use_build_context_synchronously` updated to recognize nullable types when
   accessed from legacy libraries.
 
+#### Pub
+
+* `dart pub publish` now respects `.pubignore` files with gitignore-style rules.
+ `.gitignore` files in the repo are still respected if they are not
+  overridden by a `.pubignore` in the same directory.
+
+  pub no longer queries git for listing the files. This implies:
+  * Checked in files will now be ignored if they are included by a `.gitignore`
+    rule.
+  * Global ignores are no longer taken into account.
+  * Even packages that are not in git source control will have their
+    `.gitignore` files respected.
+
+* New flag `dart pub deps --json` gives a machine parsable overview of the
+  current dependencies.
+* New command: `dart pub cache clean`. Will delete everything in your current
+  pub cache.
+* Commands related to a single package now takes a `--directory` option to
+  operate on a package in the given directory instead of the working directory.
+* git dependencies with a relative repo url would previously be interpreted
+  relative to the current package, even for transitive dependencies. This now
+  fails instead.
+
+* Pub now uses a Dart library to read and write tar files.
+  This should fix several issues we had with incompatibilities between different
+  system `tar`s.
+* `PUB_HOSTED_URL` can now include a trailing slash.
+
 ### Language
 
 *   Add an unsigned shift right operator `>>>`. Pad with zeroes, ignoring the

DEPS

@@ -141,7 +141,7 @@ vars = {
   "pool_rev": "7abe634002a1ba8a0928eded086062f1307ccfae",
   "process_rev": "56ece43b53b64c63ae51ec184b76bd5360c28d0b",
   "protobuf_rev": "0d03fd588df69e9863e2a2efc0059dee8f18d5b2",
-  "pub_rev": "0e657414a472e74ca5dd76ae0db50cc060251dec",
+  "pub_rev": "00c00e8adf9706bebe8f94483b7663c5f36f59d2",
   "pub_semver_rev": "f50d80ef10c4b2fa5f4c8878036a4d9342c0cc82",
   "resource_rev": "6b79867d0becf5395e5819a75720963b8298e9a7",
   "root_certificates_rev": "7e5ec82c99677a2e5b95ce296c4d68b0d3378ed8",