tracing: prepare to release v0.1.40

# 0.1.40

This release fixes a potential stack use-after-free in the
`Instrument::into_inner` method. Only uses of this method are affected
by this bug.

### Fixed

- Use `mem::ManuallyDrop` instead of `mem::forget` in
  `Instrument::into_inner` (#2765)

[#2765]: #2765

Thanks to @cramertj and @Manishearth for finding and fixing this issue!

tracing/CHANGELOG.md

@@ -1,3 +1,18 @@
+# 0.1.40
+
+This release fixes a potential stack use-after-free in the
+`Instrument::into_inner` method. Only uses of this method are affected by this
+bug.
+
+### Fixed
+
+- Use `mem::ManuallyDrop` instead of `mem::forget` in `Instrument::into_inner`
+  ([#2765])
+
+[#2765]: https://github.com/tokio-rs/tracing/pull/2765
+
+Thanks to @cramertj and @manishearth for finding and fixing this issue!
+
 # 0.1.39 (October 12, 2023)
 
 This release adds several additional features to the `tracing` macros. In

tracing/Cargo.toml

@@ -8,7 +8,7 @@ name = "tracing"
 #   - README.md
 # - Update CHANGELOG.md.
 # - Create "v0.1.x" git tag
-version = "0.1.39"
+version = "0.1.40"
 authors = ["Eliza Weisman <eliza@buoyant.io>", "Tokio Contributors <team@tokio.rs>"]
 license = "MIT"
 readme = "README.md"