[beta] [deps] rev dartdoc

This is an accumulation of 12 commits to dartdoc, imported into
dart-lang/sdk across 4 commits, noted below. I've also stripped out
the changes made to any other repository in this DEPS file.

Revisions updated by `dart tools/rev_sdk_deps.dart`.

From cabf333:
dartdoc (https://github.com/dart-lang/dartdoc/compare/eb90a44..1f42216):
  1f422163  2022-12-13  Sam Rawlins  Bump to 6.1.5 (#3274)

From a3b7a76:
  eb90a44c  2022-12-12  Sam Rawlins      Remove annotations from the features section of each element (#3268)
  16126376  2022-12-12  Parker Lougheed  Don't show null in search results when no description (#3273)
  3ff7aa75  2022-12-12  Sam Rawlins      Fix search arrows by using a flat list of suggestions (#3271)
  90264fb4  2022-12-12  dependabot[bot]  Bump github/codeql-action from 2.1.35 to 2.1.36 (#3270)
  bede500d  2022-12-12  Sam Rawlins      Fix remote linking in 2.18 and 3.0.0 (#3267)

From 0c14719:
dartdoc (https://github.com/dart-lang/dartdoc/compare/4d7dc93..f2bb6e9):
  f2bb6e92  2022-12-07  Sam Rawlins  Bump to 6.1.4 (#3266)

From 3a1d7c7:
dartdoc (https://github.com/dart-lang/dartdoc/compare/dc502d0..4d7dc93):
  4d7dc93b  2022-12-05  dependabot[bot]  Bump github/codeql-action from 2.1.31 to 2.1.35 (#3263)
  bcf8b6e8  2022-12-05  Parker Lougheed  Weight enums the same as classes for searching (#3260)
  7d95578b  2022-12-04  Parker Lougheed  Update template descriptions (#3258)
  d558f043  2022-12-04  Parker Lougheed  Fix error when using base element href (#3256)
  c3663762  2022-12-04  Parker Lougheed  Add unnecessary override ignore to fix build (#3257)

Change-Id: I21fc9ecd36db78b7ef420bd179af4907e667557d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/279320
Reviewed-by: Kevin Moore <kevmoo@google.com>
Commit-Queue: Kevin Chisholm <kevinjchisholm@google.com>

DEPS

@@ -125,7 +125,7 @@ vars = {
   # For more details, see https://github.com/dart-lang/sdk/issues/30164.
   "dart_style_rev": "f79a9828ad07e50d6e8352ac154cc16eb4d78d5c", # manually rev'd
 
-  "dartdoc_rev": "dc502d0862fe1ba8451c9c57cd7ab70432634af3",
+  "dartdoc_rev": "1f4221632777d21a7c0d0a0266fe6a495f5170ce",
   "devtools_rev": "dd3fade2bd2ef74fc6102e56333a48f0efc594d3",
   "ffi_rev": "17a8142da8114a065e03200467c7657b5368a86d",
   "file_rev": "b768f79dcd104a5feabafab47101c4355b71cd8f",