[deps] Update webdev_rev

See https://github.com/dart-lang/webdev/compare/b9c39c00853dfad0e235bec3b265f86a0f4f328a..234e44c2ba0aa6cee5a36026538ca89457bf0d55.

```
$ git log --pretty='%h %s %ae' b9c39c00..234e44c
234e44c2 Bump the github-actions group across 1 directory with 2 updates (#2723) 49699333+dependabot[bot]@users.noreply.github.com
40bbcde1 Fix awaiting for  future [email protected]
a407cc15 Remove unset `clientFuture` (#2718) [email protected]
71c052cc Syncing frontend_server_client Package with Dart SDK (#2716) [email protected]
56642b75 Fix setting g3 breakpoints (#2713) [email protected]
bb5af96f Bump `build_web_compilers` to `^4.4.1` (#2711) [email protected]
733af11c [ DWDS ] Correctly report the current pause state for the WebSocketProxyService (#2710) [email protected]
be9f117f [ DWDS ] Prepare for 26.2.1 release (#2708) [email protected]
382ff428 [ DWDS ] Launch DDS when using the web socket proxy service (#2706) [email protected]
```


Change-Id: I7333737a341177ea58d29c76d47e99febce40a50
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/463581
Auto-Submit: Ivan Inozemtsev <[email protected]>
Commit-Queue: Ben Konyi <[email protected]>
Commit-Queue: Ivan Inozemtsev <[email protected]>
Reviewed-by: Ben Konyi <[email protected]>

Author: iinozemtsev

DEPS

@@ -150,7 +150,7 @@ vars = {
   "tools_rev": "d03c394b24829f662098e590a2c812a076b01199",
   "vector_math_rev": "70a9a2cb610d040b247f3ca2cd70a94c1c6f6f23",
   "web_rev": "35fc98dd8f9da175ed0a2dcf246299e922e1e1e2",
-  "webdev_rev": "b9c39c00853dfad0e235bec3b265f86a0f4f328a",
+  "webdev_rev": "234e44c2ba0aa6cee5a36026538ca89457bf0d55",
   "webdriver_rev": "09104f459ed834d48b132f6b7734923b1fbcf2e9",
   "webkit_inspection_protocol_rev": "0f7685804d77ec02c6564d7ac1a6c8a2341c5bdf",