Bump dartdoc to 53222e20f3a82211a038de4e1710fd57b0403652

Adapts dartdev to simplified interface

Changes:
```
> git log --format="%C(auto) %h %s" d683b47..53222e2
 https://dart.googlesource.com/dartdoc.git/+/53222e20 Small cleanup around generators (4096)
 https://dart.googlesource.com/dartdoc.git/+/43e623bc Remove duplicated getter in package_graph.dart (4094)
 https://dart.googlesource.com/dartdoc.git/+/435198fd Refactor handling of generateDocs:false (4095)
 https://dart.googlesource.com/dartdoc.git/+/8b4d03e6 Add test for dot shorthands in constant initializers (4093)
 https://dart.googlesource.com/dartdoc.git/+/e20f1beb Add tests for dot shorthands in annotations and default values (4092)
 https://dart.googlesource.com/dartdoc.git/+/4ac49cfd Remove unnecessary src imports (4090)
 https://dart.googlesource.com/dartdoc.git/+/64e4647d Add test for dot shorthands (4089)

```

Diff: https://dart.googlesource.com/dartdoc.git/+/d683b47abc407a3093c269f67ed4c66b98138d56..53222e20f3a82211a038de4e1710fd57b0403652/
Change-Id: Ieb533070f4943a525aab6f91fbc5cd01cd4a6fd2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/447720
Reviewed-by: Sarah Zakarias <[email protected]>
Commit-Queue: Sigurd Meldgaard <[email protected]>

Author: sigurdm

DEPS

@@ -133,7 +133,7 @@ vars = {
   # EOL comment after a dependency to instead pin at the current revision.
   "ai_rev": "1547a834d8a3bb021f2e6c49c41d5aaad11a5b7f",
   "core_rev": "5c3e2c38df268be2347f3aad30ced0147dd012bb",
-  "dartdoc_rev": "d683b47abc407a3093c269f67ed4c66b98138d56",
+  "dartdoc_rev": "53222e20f3a82211a038de4e1710fd57b0403652",
   "ecosystem_rev": "36e514d52c5d056227e4cea98b784ade50b5b4f1",
   "flute_rev": "d5adc4d6439572db5da71a9261b9bf0c7c96daa4",
   "http_rev": "ef05b3744424885d93f88a6a50664fb5b7d5cbdb",

pkg/dartdev/lib/src/commands/doc.dart

@@ -114,10 +114,7 @@ For additional documentation generation options, see the 'dartdoc_options.yaml'
     final packageConfigProvider = PhysicalPackageConfigProvider();
     final packageBuilder = PubPackageBuilder(
         config, pubPackageMetaProvider, packageConfigProvider);
-    final dartdoc = config.generateDocs
-        ? Dartdoc.fromContext(config, packageBuilder)
-        : Dartdoc.withEmptyGenerator(config, packageBuilder);
-    dartdoc.executeGuarded();
+    Dartdoc.fromContext(config, packageBuilder).executeGuarded();
     return 0;
   }
 }