roll: pigweed, pw_toolchain: pw_async2: Fix minor doc issues

It turns out using code backticks in a markdown header, in a Doxygen
class comment, in an RST document doesn't quite work right. This:

   /// # Using `co_await`

Resulted in <tt>co_await</tt> being visible in the final rendered doc.
Just remove the backticks rather than trying to unwind that stack.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/226111
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
pigweed, pw_toolchain Rolled-Commits: 0792e045ef9cc27..cb5ee68a68c2c3c
Roller-URL: https://ci.chromium.org/b/8741401927843317937
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I8ec9e35f370a218265fcf0369afb551d50ffda8e
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/226022
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/WORKSPACE b/WORKSPACE
index 6ab5240..3903377 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -84,8 +84,8 @@
     name = "pigweed",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-07-25.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8741402335622225649.
-    commit = "0792e045ef9cc2769f74da65f5fee990cb4f33ba",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8741401927843317937.
+    commit = "cb5ee68a68c2c3ccf7de384de63a956c9d6ac006",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed.git",
 )
 
@@ -93,8 +93,8 @@
     name = "pw_toolchain",
     # ROLL: Warning: this entry is automatically updated.
     # ROLL: Last updated 2024-07-25.
-    # ROLL: By https://cr-buildbucket.appspot.com/build/8741402335622225649.
-    commit = "0792e045ef9cc2769f74da65f5fee990cb4f33ba",
+    # ROLL: By https://cr-buildbucket.appspot.com/build/8741401927843317937.
+    commit = "cb5ee68a68c2c3ccf7de384de63a956c9d6ac006",
     remote = "https://pigweed.googlesource.com/pigweed/pigweed.git",
     strip_prefix = "pw_toolchain_bazel",
 )